Search

The cultural characteristics that differentiate Japan and US are presented. The impact of Japanese business culture and political culture on endogenous policy formation in post-WWII Japan are examined.

This study has revealed that a Clostridium perfringens ferredoxin gene (per-fdx) possesses a novel type of DNA curvature, which is formed by five phased A-tracts extending from upstream to downstream of the -35 region. The three A-tracts upstream of the promoter and the two within the promoter are located at the positions corresponding to A-tracts present in a C. perfringens phospholipase C gene (plc) and a Clostridium pasteurianum ferredoxin gene (pas-fdx), respectively. DNA fragments of the per-fdx, pas-fdx and plc genes (nucleotide positions -69 to + 1 relative to the transcription initiation site) were fused to a chloramphenicol acetyltransferase reporter gene on a plasmid, pPSV, and their in vivo promoter activities were examined by assaying the chloramphenicol acetyltransferase activity of each C. perfringens transformant. Comparison of the three constructs showed that the order of promoter activity is, in descending order, per-fdx, pas-fdx and plc. Deletion of the three upstream A-tracts of the per-fdx gene drastically decreased the promoter activity, as demonstrated previously for the plc promoter. Substitution of the most downstream A-tract decreased the promoter activities of the per-fdx and pas-fdx genes. These results indicate that not only the phased A-tracts upstream of the promoter but also those within the promoter stimulate the promoter activity, and suggest that the high activity of the per-fdx promoter is due to the combined effects of these two types of A-tracts.

Analysis of nitrate reductase operon shows that it is a 9.5 kilobase fragment containing seven open reading frames (ORFs). Nitrate reductase, ferredoxin-like protein, and NADH oxidase are coded by ORF4, 5, and 6 respectively, indicating they are putative genes of nitrate reduction system of Clostridium perfringens.

Research was conducted to examine a new subfamily of gluzincins and a possible role for the glutamate residues around the third zinc ligand in the formation of the catalytic center of clostridial collagenases. The codons corresponding to the three conserved residues in the motif were mutated to other amino acid residues. The mutation influencing His415 or His419 abolished catalytic activity and zinc binding while that influencing Glu 446 did the former but not the latter. Results indicate that the two residues are also involved in catalysis.

The relationship of monopolist with resource conservationist is evaluated based on the aspects of uncertainty and competitive market pressure of entry. Monopolist's view of the reserve of the exhaustible resource tends to be influenced by demand uncertainty. Monopolist tend to maintain a smaller reserve whenever there is a fluctuation in demand and the risk is high. Extraction policy, meanwhile, is affected by competitive market pressure related to entry.

The in vivo transcriptional activity of the plasmid-borne plc gene, which encodes phospholipase C (alpha-toxin) of Clostridium perfringens, was stimulated by a curved-DNA-containing sequence, depending on its proper linear and rotational orientation. The transcriptional activity was also stimulated by the upstream sequence. Moreover, the stimulatory effect of the sequence and the degree of DNA bending were greater at lower temperature. A similar temperature effect was also seen with the chromosomal plc gene.

Fibronectin (Fn) is an approximately 450 kDa glycoprotein that consists of 12 type I, 2 type II, and 15–17 type III modules. Fibrillation of Fn is important for tissue reconstitution and wound healing. We previously reported that Clostridium perfringens produces several Fn‐binding proteins (Fbps), two of which, FbpA and FbpB, bind to III1‐C (a fragment of Fn derived from the carboxyl‐terminal two‐thirds of the first‐type III module). Dermatopontin (DPT), a 22 kDa noncollagenous extracellular matrix protein, accelerates normal collagen fibrillation and induces Fn fibrillation. DPT interacts with Fn‐type III12–14 (III12–14), leading to a change in Fn conformation and promoting Fn fibrillation. Here, we investigated the effects of FbpA and FbpB on the binding of Fn and the III12–14 fragment to DPT and on the DPT‐induced Fn fibrillation. Both recombinant FbpA (rFbpA) and recombinant FbpB (rFbpB) significantly inhibited Fn binding to DPT and recombinant III12–14 (rIII12–14) binding, and inhibited DPT‐induced Fn fibrillation. Furthermore, it was found that both rFbpA and rFbpB significantly bound to coated DPT in an enzyme‐linked avidin–biotin complex system, whereas rIII12–14 did not bind to either coated rFbpA or rFbpB. In conclusion, both FbpA and FbpB inhibited DPT‐induced Fn fibrillation via their interaction with DPT. Both FbpA and FbpB released from lysed C. perfringens cells in wounds and/or infected tissue may prevent Fn fibrillation and delay the wound healing process, subsequently exacerbating infection. [ABSTRACT FROM AUTHOR]

Pili in Gram‐positive bacteria are flexible rod proteins associated with the bacterial cell surface, and they play important roles in the initial adhesion to host tissues and colonization. The pilus shaft is formed by the covalent polymerization of major pilins, catalyzed by sortases, a family of cysteine transpeptidases. Here, X‐ray structures of the major pilins from Clostridium perfringens strains 13 and SM101 and of sortase from strain SM101 are presented with biochemical analysis to detect the formation of pili in vivo. The major pilin from strain 13 adopts an elongated structure to form noncovalently linked polymeric chains in the crystal, yielding a practical model of the pilus fiber structure. The major pilin from strain SM101 adopts a novel bent structure and associates to form a left‐handed twist like an antiparallel double helix in the crystal, which is likely to promote bacterial cell–cell interactions. A modeling study showed that pilin with a bent structure interacts favorably with sortase. The major pilin from strain SM101 was considered to be in an equilibrium state between an elongated and a bent structure through dynamic conformational change, which may be involved in pili‐mediated colonization and sortase‐mediated polymerization of pili. [ABSTRACT FROM AUTHOR]