Overproduction or absence of the periplasmic protease DegP severely compromises bacterial growth in the absence of the dithiol: disulfide oxidoreductase DsbA.

ABSTRACT: Facultative phototrophic bacterium Rhodobacter capsulatus DsbA-null mutants are proficient in photosynthesis but are defective in respiration especially in enriched growth medium at 35 degrees C. They also exhibit severe pleiotropic phenotypes extending from motility defects to osmofragility and oxidative stresses. In this work, using a combined proteomics and molecular genetics approach, we demonstrated that the respiratory defect of R. capsulatus DsbA-null mutants originates from the overproduction of the periplasmic protease DegP, which renders them temperature-sensitive for growth. The DsbA-null mutants reverted frequently to overcome this growth defect by decreasing, but not completely eliminating, their DegP activity. In agreement with these findings, we showed that overproduction of

SUBMITTER: Onder O 

PROVIDER: S-EPMC2401338 | biostudies-literature | 2008 May

REPOSITORIES: biostudies-literature