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Sufu (Suppressor of Fused), a two-domain protein, plays a critical role in regulating Hedgehog signaling and is conserved from flies to humans. A few bacterial Sufu-like proteins have previously been identified based on sequence similarity to the N-terminal domain of eukaryotic Sufu proteins, but none have been structurally or biochemically characterized and their function in bacteria is unknown. We have determined the crystal structure of a more distantly related Sufu-like homolog, NGO1391 from Neisseria gonorrhoeae, at 1.4 A resolution, which provides the first biophysical characterization of a bacterial Sufu-like protein. The structure revealed a striking similarity to the N-terminal domain of human Sufu (r.m.s.d. of 2.6 A over 93% of the NGO1391 protein), despite an extremely low sequence identity of ∼15%. Subsequent sequence analysis revealed that NGO1391 defines a new subset of smaller, Sufu-like proteins that are present in ∼200 bacterial species and has resulted in expansion of the SUFU (PF05076) family in Pfam.

The crystal structure of BT_3984, a SusD-family protein, reveals a TPR N-terminal region providing support for a loop-rich C-terminal subdomain and suggests possible interfaces involved in sus complex formation., The crystal structure of the Bacteroides thetaiotaomicron protein BT_3984 was determined to a resolution of 1.7 Å and was the first structure to be determined from the extensive SusD family of polysaccharide-binding proteins. SusD is an essential component of the sus operon that defines the paradigm for glycan utilization in dominant members of the human gut microbiota. Structural analysis of BT_3984 revealed an N-terminal region containing several tetratricopeptide repeats (TPRs), while the signature C-terminal region is less structured and contains extensive loop regions. Sequence and structure analysis of BT_3984 suggests the presence of binding interfaces for other proteins from the polysaccharide-utilization complex.

The crystal structure of BT2081 from B. thetaiotaomicron reveals a two-domain protein with a putative carbohydrate-binding site in the C-­terminal domain., BT2081 from Bacteroides thetaiotaomicron (GenBank accession code NP_810994.1) is a member of a novel protein family consisting of over 160 members, most of which are found in the different classes of Bacteroidetes. Genome-context analysis lends support to the involvement of this family in carbohydrate metabolism, which plays a key role in B. thetaiotaomicron as a predominant bacterial symbiont in the human distal gut microbiome. The crystal structure of BT2081 at 2.05 Å resolution represents the first structure from this new protein family. BT2081 consists of an N-terminal domain, which adopts a β-sandwich immunoglobulin-like fold, and a larger C-terminal domain with a β-sandwich jelly-roll fold. Structural analyses reveal that both domains are similar to those found in various carbohydrate-active enzymes. The C-terminal β-jelly-roll domain contains a potential carbohydrate-binding site that is highly conserved among BT2081 homologs and is situated in the same location as the carbohydrate-binding sites that are found in structurally similar glycoside hydrolases (GHs). However, in BT2081 this site is partially occluded by surrounding loops, which results in a deep solvent-accessible pocket rather than a shallower solvent-exposed cleft.

The first structures from the FmdE Pfam family (PF02663) reveal that some members of this family form tightly intertwined dimers consisting of two domains (N-terminal α+β core and C-terminal zinc-finger domains), whereas others contain only the core domain. The presence of the zinc-finger domain suggests that some members of this family may perform functions associated with transcriptional regulation, protein–protein interaction, RNA binding or metal-ion sensing., Examination of the genomic context for members of the FmdE Pfam family (PF02663), such as the protein encoded by the fmdE gene from the methanogenic archaeon Methanobacterium thermoautotrophicum, indicates that 13 of them are co-transcribed with genes encoding subunits of molybdenum formylmethanofuran dehydrogenase (EC 1.2.99.5), an enzyme that is involved in microbial methane production. Here, the first crystal structures from PF02663 are described, representing two bacterial and one archaeal species: B8FYU2_DESHY from the anaerobic dehalogenating bacterium Desulfito­bacterium hafniense DCB-2, Q2LQ23_SYNAS from the syntrophic bacterium Syntrophus aciditrophicus SB and Q9HJ63_THEAC from the thermoacidophilic archaeon Thermoplasma acidophilum. Two of these proteins, Q9HJ63_THEAC and Q2LQ23_SYNAS, contain two domains: an N-terminal thioredoxin-like α+β core domain (NTD) consisting of a five-stranded, mixed β-sheet flanked by several α-helices and a C-terminal zinc-finger domain (CTD). B8FYU2_DESHY, on the other hand, is composed solely of the NTD. The CTD of Q9HJ63_THEAC and Q2LQ23_SYNAS is best characterized as a treble-clef zinc finger. Two significant structural differences between Q9HJ63_THEAC and Q2LQ23_SYNAS involve their metal binding. First, zinc is bound to the putative active site on the NTD of Q9HJ63_THEAC, but is absent from the NTD of Q2LQ23_SYNAS. Second, whereas the structure of the CTD of Q2LQ23_SYNAS shows four Cys side chains within coordination distance of the Zn atom, the structure of Q9HJ63_THEAC is atypical for a treble-cleft zinc finger in that three Cys side chains and an Asp side chain are within coordination distance of the zinc.

The crystal structure of the prephenate dehydrogenase component of the bifunctional H. influenzae TyrA reveals unique structural differences between bifunctional and monofunctional TyrA enzymes., Chorismate mutase/prephenate dehydrogenase from Haemophilus influenzae Rd KW20 is a bifunctional enzyme that catalyzes the rearrangement of chorismate to prephenate and the NAD(P)+-dependent oxidative decarboxyl­ation of prephenate to 4-hydroxyphenylpyruvate in tyrosine biosynthesis. The crystal structure of the prephenate dehydrogenase component (HinfPDH) of the TyrA protein from H. influenzae Rd KW20 in complex with the inhibitor tyrosine and cofactor NAD+ has been determined to 2.0 Å resolution. HinfPDH is a dimeric enzyme, with each monomer consisting of an N-terminal α/β dinucleotide-binding domain and a C-terminal α-helical dimerization domain. The structure reveals key active-site residues at the domain interface, including His200, Arg297 and Ser179 that are involved in catalysis and/or ligand binding and are highly conserved in TyrA proteins from all three kingdoms of life. Tyrosine is bound directly at the catalytic site, suggesting that it is a competitive inhibitor of HinfPDH. Comparisons with its structural homologues reveal important differences around the active site, including the absence of an α–β motif in HinfPDH that is present in other TyrA proteins, such as Synechocystis sp. arogenate dehydrogenase. Residues from this motif are involved in discrimination between NADP+ and NAD+. The loop between β5 and β6 in the N-terminal domain is much shorter in HinfPDH and an extra helix is present at the C-terminus. Furthermore, HinfPDH adopts a more closed conformation compared with TyrA proteins that do not have tyrosine bound. This conformational change brings the substrate, cofactor and active-site residues into close proximity for catalysis. An ionic network consisting of Arg297 (a key residue for tyrosine binding), a water molecule, Asp206 (from the loop between β5 and β6) and Arg365′ (from the additional C-terminal helix of the adjacent monomer) is observed that might be involved in gating the active site.

The crystal structure of a novel MACPF protein, which may play a role in the adaptation of commensal bacteria to host environments in the human gut, was determined and analyzed., Membrane-attack complex/perforin (MACPF) proteins are transmembrane pore-forming proteins that are important in both human immunity and the virulence of pathogens. Bacterial MACPFs are found in diverse bacterial species, including most human gut-associated Bacteroides species. The crystal structure of a bacterial MACPF-domain-containing protein BT_3439 (Bth-MACPF) from B. thetaiotaomicron, a predominant member of the mammalian intestinal microbiota, has been determined. Bth-MACPF contains a membrane-attack complex/perforin (MACPF) domain and two novel C-terminal domains that resemble ribonuclease H and interleukin 8, respectively. The entire protein adopts a flat crescent shape, characteristic of other MACPF proteins, that may be important for oligomerization. This Bth-MACPF structure provides new features and insights not observed in two previous MACPF structures. Genomic context analysis infers that Bth-MACPF may be involved in a novel protein-transport or nutrient-uptake system, suggesting an important role for these MACPF proteins, which were likely to have been inherited from eukaryotes via horizontal gene transfer, in the adaptation of commensal bacteria to the host environment.

The crystal structure of BT1062 from Bacteroides thetaiotaomicron revealed a conserved fold that is widely adopted by fimbrial components., BT1062 from Bacteroides thetaiotaomicron is a homolog of Mfa2 (PGN0288 or PG0179), which is a component of the minor fimbriae in Porphyromonas gingivalis. The crystal structure of BT1062 revealed a conserved fold that is widely adopted by fimbrial components.

Mre11 nuclease plays a central role in the repair of cytotoxic and mutagenic DNA double-strand breaks. As X-ray structural information has been available only for the Pyrococcus furiosus enzyme (PfMre11), the conserved and variable features of this nuclease across the domains of life have not been experimentally defined. Our crystal structure and biochemical studies demonstrate that TM1635 from Thermotoga maritima, originally annotated as a putative nuclease, is an Mre11 endo/exonuclease (TmMre11) and the first such structure from eubacteria. TmMre11 and PfMre11 display similar overall structures, despite sequence identity in the twilight zone of only approximately 20%. However, they differ substantially in their DNA-specificity domains and in their dimeric organization. Residues in the nuclease domain are highly conserved, but those in the DNA-specificity domain are not. The structural differences likely affect how Mre11 from different organisms recognize and interact with single-stranded DNA, double-stranded DNA and DNA hairpin structures during DNA repair. The TmMre11 nuclease active site has no bound metal ions, but is conserved in sequence and structure with the exception of a histidine that is important in PfMre11 nuclease activity. Nevertheless, biochemical characterization confirms that TmMre11 possesses both endonuclease and exonuclease activities on single-stranded and double-stranded DNA substrates, respectively.

The crystal structure of SSO2064, the first structural representative of Pfam family PF01796 (DUF35), reveals a two-domain architecture comprising an N-terminal zinc-ribbon domain and a C-terminal OB-fold domain. Analysis of the domain architecture, operon organization and bacterial orthologs combined with the structural features of SSO2064 suggests a role involving acyl-CoA binding for this family of proteins., SSO2064 is the first structural representative of PF01796 (DUF35), a large prokaryotic family with a wide phylogenetic distribution. The structure reveals a novel two-domain architecture comprising an N-terminal, rubredoxin-like, zinc ribbon and a C-terminal, oligonucleotide/oligosaccharide-binding (OB) fold domain. Additional N-terminal helical segments may be involved in protein–protein interactions. Domain architectures, genomic context analysis and functional evidence from certain bacterial representatives of this family suggest that these proteins form a novel fatty-acid-binding component that is involved in the biosynthesis of lipids and polyketide antibiotics and that they possibly function as acyl-CoA-binding proteins. This structure has led to a re-evaluation of the DUF35 family, which has now been split into two entries in the latest Pfam release (v.24.0).

The crystal structures of SPO0140 and Sbal_2486 revealed a two-domain structure that adopts a novel fold. Analysis of the interdomain cleft suggests a nucleotide-based ligand with a genome context indicating signaling as a possible role for this family., The crystal structures of SPO0140 and Sbal_2486 were determined using the semiautomated high-throughput pipeline of the Joint Center for Structural Genomics (JCSG) as part of the NIGMS Protein Structure Initiative (PSI). The structures revealed a conserved core with domain duplication and a superficial similarity of the C-terminal domain to pleckstrin homology-like folds. The conservation of the domain interface indicates a potential binding site that is likely to involve a nucleotide-based ligand, with genome-context and gene-fusion analyses additionally supporting a role for this family in signal transduction, possibly during oxidative stress.

The crystal structure of the NGO1945 gene product from N. gonorrhoeae (UniProt Q5F5IO) reveals that the N-terminal domain assigned as a domain of unknown function (DUF2063) is likely to bind DNA and that the protein may be involved in transcriptional regulation., Proteins with the DUF2063 domain constitute a new Pfam family, PF09836. The crystal structure of a member of this family, NGO1945 from Neisseria gonorrhoeae, has been determined and reveals that the N-terminal DUF2063 domain is likely to be a DNA-binding domain. In conjunction with the rest of the protein, NGO1945 is likely to be involved in transcriptional regulation, which is consistent with genomic neighborhood analysis. Of the 216 currently known proteins that contain a DUF2063 domain, the most significant sequence homologs of NGO1945 (∼40–99% sequence identity) are from various Neisseria and Haemophilus species. As these are important human pathogens, NGO1945 represents an interesting candidate for further exploration via biochemical studies and possible therapeutic intervention.

The first structural representative of the PF08866 (DUF1831) protein family reveals a potential new α+β fold and indicates a possible involvement in amino-acid metabolism., The structure of LP2179, a member of the PF08866 (DUF1831) family, suggests a novel α+β fold comprising two β-sheets packed against a single helix. A remote structural similarity to two other uncharacterized protein families specific to the Bacillus genus (PF08868 and PF08968), as well as to prokaryotic S-adenosylmethionine decarboxylases, is consistent with a role in amino-acid metabolism. Genomic neighborhood analysis of LP2179 supports this functional assignment, which might also then be extended to PF08868 and PF08968.

KPN03535 is a protein unique to K. pneumoniae. The crystal structure reveals that KPN03535 represents a novel variant of the OB-fold and is likely to be a DNA-binding lipoprotein., KPN03535 (gi|152972051) is a putative lipoprotein of unknown function that is secreted by Klebsiella pneumoniae MGH 78578. The crystal structure reveals that despite a lack of any detectable sequence similarity to known structures, it is a novel variant of the OB-fold and structurally similar to the bacterial Cpx-pathway protein NlpE, single-stranded DNA-binding (SSB) proteins and toxins. K. pneumoniae MGH 78578 forms part of the normal human skin, mouth and gut flora and is an opportunistic pathogen that is linked to about 8% of all hospital-acquired infections in the USA. This structure provides the foundation for further investigations into this divergent member of the OB-fold family.

PA1994, a Pfam PF06475 (DUF1089) family homolog from P. aeruginosa, reveals remote similarities to lipoprotein localization factors and a conserved putative glycolipid-binding site., The crystal structure of PA1994 from Pseudomonas aeruginosa, a member of the Pfam PF06475 family classified as a domain of unknown function (DUF1089), reveals a novel fold comprising a 15-stranded β-sheet wrapped around a single α-helix that assembles into a tight dimeric arrangement. The remote structural similarity to lipoprotein localization factors, in addition to the presence of an acidic pocket that is conserved in DUF1089 homologs, phospholipid-binding and sugar-binding proteins, indicate a role for PA1994 and the DUF1089 family in glycolipid metabolism. Genome-context analysis lends further support to the involvement of this family of proteins in glycolipid metabolism and indicates possible activation of DUF1089 homologs under conditions of bacterial cell-wall stress or host–pathogen interactions.

Cell cycle regulated stalk biogenesis in Caulobacter crescentus is controlled by a multi-step phosphorelay system consisting of the hybrid histidine kinase ShkA, the histidine-phosphotransfer protein ShpA and the response regulator TacA. ShpA shuttles phosphoryl groups between ShkA and TacA. When phosphorylated, TacA triggers a downstream transcription cascade for stalk synthesis in an RpoN-dependent manner. The crystal structure of ShpA was determined to 1.52 Å resolution. ShpA belongs to a family of monomeric histidine phosphotransfer (HPt) proteins, which feature a highly conserved four-helix bundle. The phosphorylatable histidine, His56, is located on the surface of the helix bundle and is fully solvent exposed. One end of the four-helix bundle in ShpA is shorter compared to other characterized histidine phosphotransfer proteins, whereas the face that potentially interacts with the response regulators is structurally conserved. Similarities of the interaction surface around the phosphorylation site suggest that ShpA is likely to share a common mechanism for molecular recognition and phosphotransfer with yeast phosphotransfer protein YPD1 despite low overall sequence similarity.

This essay aims to introduce Giovanni Gentile to scholars of Gramsci studies broadly and Gramsci‐education studies more specifically. The largest part of the essay explores Gentile's academic life, his philosophical agenda, and his political career. Having established a basis for understanding the educational reform Gentile enacted as Mussolini's first Minister of Public Instruction, the essay then surveys the substantial contemporaneous and contemporary English‐language material about it. The essay engages this literature only lightly and briefly in conclusion, for the primary purpose of illustrating the danger of eschewing it.

ECX21941 represents a very large family (over 600 members) of novel, ocean metagenome-specific proteins identified by clustering of the dataset from the Global Ocean Sampling expedition. The crystal structure of ECX21941 reveals unexpected similarity to Sm/LSm proteins, which are important RNA-binding proteins, despite no detectable sequence similarity. The ECX21941 protein assembles as a homopentamer in solution and in the crystal structure when expressed in Escherichia coli and represents the first pentameric structure for this Sm/LSm family of proteins, although the actual oligomeric form in vivo is currently not known. The genomic neighborhood analysis of ECX21941 and its homologs combined with sequence similarity searches suggest a cyanophage origin for this protein. The specific functions of members of this family are unknown, but our structure analysis of ECX21941 indicates nucleic acid-binding capabilities and suggests a role in RNA and/or DNA processing.

The protein SO4266 (gi|24375750) from the bacterium Shewanella oneidensis MR-1 is annotated as a member of Pfam PF02661. This family consists of Fic (filamentation induced by cAMP) proteins and their relatives, and is characterized by the presence of a well-conserved HPFXXGNG motif 1. The biochemistry of Fic proteins has not been characterized extensively and their exact molecular functions remain unknown. From early studies in Escherichia coli, it is believed that Fic proteins and cAMP may be involved in a regulatory mechanism of cell division, including folate metabolism by the synthesis of p-aminobenzoic acid (PABA) or folate 1. Proteins containing the Fic domain are present in all kingdoms of life and range in size from ~200 to 500 amino acids. The Fic protein family contains 647 members, including two human proteins, according to Pfam (May 2008). Sequence-based clustering 2 of this protein family, at 30% sequence identity, groups these proteins into 18 clusters. Three crystal structures of Fic proteins from bacteria (unpublished) are available in the Protein Data Bank [accession codes 2g03 (194 residues, 2.2 A), 2f6s (201 residues, 2.5 A) and 3cuc (262 residues, 2.7 A)]. The first two of these proteins belong to a single cluster of 16 members and share ~60% sequence identity. The anti-apoptotic bacterial effector protein BepA, which is a type IV secretion (T4S) system substrate, also contains an N-terminal Fic domain 3. In humans, the Fic domain is present in the Huntingtin Interacting Protein E (HYPE; Uniprot entry Q9BVA6_HUMAN), a protein of unknown function that is thought to interact with Huntingtin, one of the major proteins in the Huntington's disease protein interaction network (listed as NAD- or FAD-binding) 4. Bioinformatics analysis of prokaryotic toxin-antitoxin networks 5 suggests that Fic proteins are putative death-on-curing (Doc) toxins that are part of the Phd-Doc system. These proteins likely function as metal-dependent nucleases or RNA-processing enzymes, 5 while more recent studies suggest that Doc toxicity is caused by inhibition of translation elongation 6. SO4266 (Uniprot entry Q8E9K5_SHEON), at 372 amino acids, is one of the largest Fic domain-containing proteins to have its structure determined. Interestingly, both HYPE and SO4266 belong to the largest sequence cluster in this family (n.b. our B. thetaiotaomicron {"type":"entrez-protein","attrs":{"text":"NP_811426.1","term_id":"29347923","term_text":"NP_811426.1"}}NP_811426.1 structure with PDB id 3cuc also belongs to this cluster), which comprises 466 out of 647 proteins, and share ~32% sequence identity in the Fic domain. Here, we report the crystal structure of the SO4266 protein at 1.6 A resolution. The structure reveals a dimeric protein with additional electron density in the vicinity of the highly conserved HPFXXGNG motif in the Fic domain of one subunit that corresponds to the N-terminus of a symmetry-related molecule. In addition, the study also reveals a C-terminal winged-helix DNA-binding domain that sets it apart from the other Fic protein structures. The structure presented here is a representative of the largest sequence cluster and together with the structures of the other Fic proteins paves the way for further structure-based functional characterization.

Signal transduction ATPases with numerous domains (STAND), a large class of P-loop NTPases, belong to AAA+ ATPases. They include AP(apoptotic)-ATPases (e.g., animal apoptosis regulators CED4/Apaf-1, plant disease resistance proteins, and bacterial AfsR-like transcription regulators), NACHT NTPases (e.g. CARD4, NAIP, Het-E-1, TLP1), and several other less well-characterized families. STAND differ from other P-loop NTPases by their unique sequence motifs, which include an hhGRExE (h, hydrophobic; x, any residue) motif at the N-terminal region, a GxP/GxxP motif at the C-terminal region of the NTPase domain, in addition to a C-terminal helical domain and additional domains such as WD40, TPR, LRR or catalytic modules. Despite significant biological interests, structural coverage of STAND proteins is very limited and only two other structures are currently known: the cell death regulators Apaf-1 and CED-4. Here, we report the crystal structure of SSO1545 from Sulfolobus solfataricus, which was determined using the semi-automated, high-throughput pipeline of the Joint Center for Structural Genomics (JCSG; http://www.jcsg.org), as part of the National Institute of General Medical Sciences' Protein Structure Initiative (PSI). SSO1545 (NP-342973.1), a representative of the archaeal STANDs, is a member of Pfam PF01637 and encodes a protein of 356 residues with calculated molecular weight and isoelectric point of 41.7more » kD and 8.2, respectively.« less

To extend the structural coverage of proteins with unknown functions, we targeted a novel protein family (Pfam accession number PF08807, DUF1798) for which we proposed and determined the structures of two representative members. The MW1337R gene of Staphylococcus aureus subsp. aureus Rosenbach (Wood 46) encodes a protein with a molecular weight of 13.8 kDa (residues 1-116) and a calculated isoelectric point of 5.15. The lin2004 gene of the nonspore-forming bacterium Listeria innocua Clip11262 encodes a protein with a molecular weight of 14.6 kDa (residues 1-121) and a calculated isoelectric point of 5.45. MW1337R and lin2004, as well as their homologs, which, so far, have been found only in Bacillus, Staphylococcus, Listeria, and related genera (Geobacillus, Exiguobacterium, and Oceanobacillus), have unknown functions and are annotated as hypothetical proteins. The genomic contexts of MW1337R and lin2004 are similar and conserved in related species. In prokaryotic genomes, most often, functionally interacting proteins are coded by genes, which are colocated in conserved operons. Proteins from the same operon as MW1337R and lin2004 either have unknown functions (i.e., belong to DUF1273, Pfam accession number PF06908) or are similar to ypsB from Bacillus subtilis. The function of ypsB is unclear, although it has a strong similaritymore » to the N-terminal region of DivIVA, which was characterized as a bifunctional protein with distinct roles during vegetative growth and sporulation. In addition, members of the DUF1273 family display distant sequence similarity with the DprA/Smf protein, which acts downstream of the DNA uptake machinery, possibly in conjunction with RecA. The RecA activities in Bacillus subtilis are modulated by RecU Holliday-junction resolvase. In all analyzed cases, the gene coding for RecU is in the vicinity of MW1337R, lin2004, or their orthologs, but on a different operon located in the complementary DNA strand. Here, we report the crystal structures of MW1337R and lin2004, which were determined using the semiautomated, high-throughput pipeline of the Joint Center for Structural Genomics (JCSG), part of the National Institute of General Medical Sciences Protein Structure Initiative.« less

TyrA is a member of the dye-decolorizing peroxidase (DyP) family, a new family of heme-dependent peroxidase recently identified in fungi and bacteria. Here, we report the crystal structure of TyrA in complex with iron protoporphyrin (IX) at 2.3 A. TyrA is a dimer, with each monomer exhibiting a two-domain, alpha/beta ferredoxin-like fold. Both domains contribute to the heme-binding site. Co-crystallization in the presence of an excess of iron protoporphyrin (IX) chloride allowed for the unambiguous location of the active site and the specific residues involved in heme binding. The structure reveals a Fe-His-Asp triad essential for heme positioning, as well as a novel conformation of one of the heme propionate moieties compared to plant peroxidases. Structural comparison to the canonical DyP family member, DyP from Thanatephorus cucumeris (Dec 1), demonstrates conservation of this novel heme conformation, as well as residues important for heme binding. Structural comparisons with representative members from all classes of the plant, bacterial, and fungal peroxidase superfamily demonstrate that TyrA, and by extension the DyP family, adopts a fold different from all other structurally characterized heme peroxidases. We propose that a new superfamily be added to the peroxidase classification scheme to encompass the DyP family of heme peroxidases.

African American males are underrepresented in higher education, but for those who enroll in institutions of higher education, most begin the journey by enrolling at a community college. Using a phenomenological design, this study sought to explore the lived experiences of African American male community college students by exploring masculinity and its impact on persistence and academic success at the community college. Five African American male students attending a community college in Texas were interviewed using Seidman’s three-interview process. Each interview followed a semi-structured interview protocol in order to establish dialogue between the participants and the researcher. Interpretive analysis was used to explore experiences of the participants of this study. Findings produced three themes: (1) perceptions of masculinity influenced by African American identities; (2) masculinity’s impact on education as a pathway and academic success, and (3) factors influencing success. The results illustrate how African American male students are able to overcome obstacles to obtain academic success regardless of ingrained perceptions of masculinity, race and academic challenges. With the increasing numbers of African American males in community colleges, higher education administrators and leaders will have to ensure there are processes where students adapting to the new experiences of college do not feel anxious, frustrated, or inadequate.

NANOG (from Irish mythology Tir na nOg) transcription factor plays a central role in maintaining pluripotency, cooperating with OCT4 (also known as POU5F1 or OCT3/4), SOX2, and other pluripotency factors. Although the physiological roles of the NANOG protein have been extensively explored, biochemical and biophysical properties in relation to its structural analysis are poorly understood. Here we determined the crystal structure of the human NANOG homeodomain (hNANOG HD) bound to an OCT4 promoter DNA, which revealed amino acid residues involved in DNA recognition that are likely to be functionally important. We generated a series of hNANOG HD alanine substitution mutants based on the protein-DNA interaction and evolutionary conservation and determined their biological activities. Some mutant proteins were less stable, resulting in loss or decreased affinity for DNA binding. Overexpression of the orthologous mouse NANOG (mNANOG) mutants failed to maintain self-renewal of mouse embryonic stem cells without leukemia inhibitory factor. These results suggest that these residues are critical for NANOG transcriptional activity. Interestingly, one mutant, hNANOG L122A, conversely enhanced protein stability and DNA-binding affinity. The mNANOG L122A, when overexpressed in mouse embryonic stem cells, maintained their expression of self-renewal markers even when retinoic acid was added to forcibly drive differentiation. When overexpressed in epiblast stem cells or human induced pluripotent stem cells, the L122A mutants enhanced reprogramming into ground-state pluripotency. These findings demonstrate that structural and biophysical information on key transcriptional factors provides insights into the manipulation of stem cell behaviors and a framework for rational protein engineering.

In recent years, Cambodia has transitioned from a communist state to a liberal democracy following market economic practices. Transition in the political economy has, in turn, influenced education and, more specifically, moral education. In this article, I define moral education more broadly than many, as additionally dedicated to the preparation of students ideologically for participation in, or opposition to, political and economic movements at the world level. During successive communist regimes (Democratic Kampuchea, 1975–1979, and the People's Republic of Kampuchea, 1979–1989), Cambodian governments used education to prepare ‘new’ men and women capable of participation in, or withdrawal from, the international socialist revolution. Beyond advancing ways of thinking and acting appropriate in contemporary Cambodian society, moral education in the State of Cambodia (1989–1993) and the Kingdom of Cambodia (1993–present) is preparing students for participation in the world to which democratization and lib...

In recent years, many scholars have become fascinated by a contemporary, multidimensional process that has come to be known as “globalization.” Globalization originally described economic developments at the world level. More specifically, scholars invoked the concept in reference to the process of global economic integration and the seemingly inexorable movement toward a single economy and a single division of labor in the world. For Leslie Sklair, globalization thus refers (among other things) to the “emergence of a globalized economy based on new systems of production, finance and consumption.” Terry Boswell and Christopher Chase-Dunn understand the economic dimension of globalization similarly, as the evolution of “transnational sourcing and a single interdependent global economy” facilitated by “foreign investment, information exchange, . . . world cultural commercialization, [and] the integration of trade and production.” Beyond economic inquiry, the globalization concept has proved quite useful in exploring other recent world-level processes and developments. Scholars have studied world cultural and political integration, for instance, as dimensions of globalization; it is in such contributions that we encounter references to the “MacDonaldization” or “Americanization” of culture and to the “withering” or “retreat” of the nation-state. A casual scan through any library database illustrates the ever-more specific applications of the globalization concept to such realms as health policies, music, ethnicity, gender

Cambodia offers an intriguing case study for the international spread of English. As a result of the multiple transitions the country is currently undergoing, English has increased dramatically in status in the last decade, essentially displacing French as the international language of choice. At the descriptive level, this article charts the spread of English into Cambodia, along side French efforts to contest this spread in favor of French. At the theoretical level, this article extrapolates from the case study to make a comment in the on going debate among scholars about English language spread. The Cambodian case contributes to this debate in several ways, notably in affirming or challenging the multinational attachments of English, the communicative inequality that English use may create, the economic exploitation that may result from the establishment of English in developing countries, and the resistance to English that may emerge in settings into which the language is spreading.

This paper examines the political dimension of the educational research undertaken by Ghanian, Guatemalan, and Malian teams as part of the 1991 to 1996, USAID-funded “ Improving Educational Quality” (IEQ) project. The following questions are addressed: (a) why were (or were not) aspects of the educational reforms studied by the researchers; (b) why were (or were not) research e ndings used in decision-making about the educational policies and practices associated with the reforms; and (c) why were particular institutional arrangements and funding levels constituted for the research and dialogue activity. In offering answers to these questions, attention is paid to local, national, and global power relations and resource distributions.