aureus PF-6463922 price infections. (c) 2013 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.”
“Streptomyces coelicolor produces at least three different catalases (catalases A, B, and C) under

different physiological conditions. Catalase B (CatB) is a developmentally regulated catalase required for proper differentiation and osmoprotection of S. coelicolor. We previously observed that the N-terminal 75(2) amino acids (aa) of CatB are cleaved off, with the remaining 75-kDa processed CatB detectable in the extracellular fraction during sporulation. We here report that either the deletion of the N-terminal 75 aa or the arginine-to-alanine substitution (R75A) at the cleavage site, but not the histidine-to-alanine substitution (H131A) Wortmannin ic50 at the catalytic site, impaired both the secretion of CatB proteins and the proper differentiation of S. coelicolor cells. The proteolytic activity responsible for the cleavage of CatB was purified and then identified as a metalloprotease, which was named as SmpA (Streptomyces metalloprotease A). The SmpA protein was newly detected after sporulation, coincident with the intracellular appearance of 75-kDa CatB, which was not detected in the smpA null mutant, confirming that SmpA indeed processes CatB in vivo. The smpA mutant

was osmosensitive as catB mutant, but it displayed delayed sporulation, with the 75-kDa CatB still detectable in the extracellular milieu. Based on these results, we propose that the post-translational else regulation of CatB, which cleaves the N-terminal 75 aa residues through SmpA is crucial for proper differentiation and osmoprotection of S. coelicolor. In the absence of SmpA, an alternative route for CatB processing may function to allow delayed sporulation. (c) 2012 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.”
“Under stressful conditions, bacteria enter a viable but non-culturable (VBNC) state in which they are alive but fail to grow on conventional media.

The molecular basis underlying this state is unknown. To identify the key gene responsible for the VBNC state in Salmonella spp., we examined a S. Typhimurium LT2 VBNC mutant, which shows a characteristic delay in entering the VBNC state. The mutant showed a higher level of expression of general stress sigma factor RpoS than wild-type LT2. The mutant carried a 99-bp in-frame deletion in the clpX gene (clpX(Delta 323-355)). ClpX is known to form a ClpXP protease complex with ClpP, which plays a role in the degradation of RpoS. To investigate the effect of clpX(Delta 323-355) on VBNC induction, Delta clpX and clpX(Delta 323-355) strains were generated from LT2 cells. Compared to LT2, the Delta clpX and clpX(Delta 323-355) strains showed greater amounts of RpoS and required a longer incubation time for induction into the VBNC state.