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Burkholderia pseudomallei is the causative agent of the lethal disease melioidosis. This bacterium infects animals and humans and is increasingly resistant to multiple antibiotics. Recently, genes associated with survival of the bacterium in the infected host have been identified. One of these genes, bpsl0741, is annotated as a hypothetical protein of 185 amino acids. Here, recombinant BPSL0741 (rBPSL0741) protein was expressed, purified, verified by mass spectrometry, crystallized and analyzed by X‐ray diffraction. rBPSL0741 was crystallized by vapor diffusion using a reservoir solution consisting of 0.2 M ammonium acetate, 0.1 M sodium acetate trihydrate pH 4.6, 30% PEG 4000. The crystals diffracted to 2.1 Å resolution using an in‐house X‐ray diffractometer and belonged to an orthorhombic space group, with unit‐cell parameters a = 62.92, b = 64.57, c = 89.16 Å. The Matthews coefficient (VM) was calculated to be 2.18 Å3 Da−1, suggesting the presence of two molecules per asymmetric unit and an estimated solvent content of 43.5%. The crystal was deemed to be suitable for further structural studies, which are currently ongoing. [ABSTRACT FROM AUTHOR]

Aims: To date, nine classes of copper regulation mechanisms have been discovered in bacteria and CsoR regulator protein is the most recent among them. Only a few have been structurally and functionally characterized. The present study was aimed to isolate and characterize the sequence, structure and biochemical properties of CsoRGz-like hypothetical protein (HP) to be potentially used as a copper sensor protein. Methodology and results: A scan of the complete genome of a Geobacillus zalihae strain T1 revealed the presence of CsoR-like (CsoRGz) HP, which contains CsoR-like_DUF156 domain and highly conserved Cys-His-Cys residues essential for copper binding. It only shares moderate sequence identity with structurally characterized CsoR proteins. CsoRGz-like HP was subjected to sequence analyses to identify important domains, motifs and residues, while circular dichroism and X-ray crystallography were used to determine its secondary and tertiary structures. CsoRGz appears to be a dimer comprising mainly a-helices, with putative, conserved metal-binding ligands, Cys46-His71-Cys75, located on the a2 helix of the protein. Biophysical characterization of CsoRGz using UV/Vis and fluorescence spectrophotometry confirmed its interaction with Cu(I). Docking of Cu(I) to the dimeric structure of CsoRGz showed that Cu(I) could be coordinated by the above metal-binding residues, further stabilized by the hydrophobic core at the metal-binding site. Conclusion, significance and impact of study: The findings in this study suggest that CsoRGz-like HP might be a novel CsoR protein. This adds to the breadth and numbers of possible CsoR proteins, particularly uncharacterized ones, existing in the pool of hypothetical proteins, to be further characterized and compared across bacterial taxa. [ABSTRACT FROM AUTHOR]

A heterologous signal peptide (SP) from Bacillus sp. G1 was optimized for secretion of recombinant cyclodextrin glucanotransferase (CGTase) to the periplasmic and, eventually, extracellular space of Escherichia coli. Eight mutant SPs were constructed using site-directed mutagenesis to improve the secretion of recombinant CGTase. M5 is a mutated SP in which replacement of an isoleucine residue in the h-region to glycine created a helix-breaking or G-turn motif with decreased hydrophobicity. The mutant SP resulted in 110 and 94% increases in periplasmic and extracellular recombinant CGTase, respectively, compared to the wild-type SP at a similar level of cell lysis. The formation of intracellular inclusion bodies was also reduced, as determined by sodium dodecyl sulfate-polyacrylamyde gel electrophoresis, when this mutated SP was used. The addition of as low as 0.08% glycine at the beginning of cell growth improved cell viability of the E. coli host. Secretory production of other proteins, such as mannosidase, also showed similar improvement, as demonstrated by CGTase production, suggesting that the combination of an optimized SP and a suitable chemical additive leads to significant improvements of extracellular recombinant protein production and cell viability. These findings will be valuable for the extracellular production of recombinant proteins in E. coli. Copyright © 2012 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Background: Various types of radiosensitisers have been introduced from the past until the present day for applications in the biomedical field. However, there is a lack of understanding and comparison between the various parameters introduced in addition to a lack of consensus among researchers on the optimal radiosensitiser for applications in the biomedical field., Objective: This review aimed to investigate the usage of radiosensitisers in the biomedical field, determine their important parameters, and suggest radiosensitisers with potential among the analysed radiosensitisers., Results and Conclusion: This review has discussed several parameters for radiosensitisers, including median lethal dose, cell survival, tumour size, cell viability, Dose Enhancement Factor (DEF), Reactive Oxygen Species (ROS) concentration, radiosensitiser production complexity, radiosensitiser administration technique, and radiosensitiser toxicity. General trends regarding the development of radiosensitisers, including the types, effectiveness, and their production complexity, have also been discussed within this review article., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)