The ?B-dependent yabJ-spoVG operon is involved in the regulation of extracellular nuclease, lipase, and protease expression in Staphylococcus aureus.

ABSTRACT: The alternative sigma factor ?(B) of Staphylococcus aureus is involved in the coordination of the general stress response, expression of virulence determinants, and modulation of antibiotic resistance levels. It controls a large regulon, either directly by recognizing conserved ?(B) promoter sequences or indirectly via ?(B)-dependent elements. The ?(B)-controlled yabJ-spoVG operon encodes two such putative downstream elements. We report here transcriptome analysis in S. aureus Newman, showing that inactivation of the yabJ-spoVG operon had primarily a repressing effect on a small subregulon encoding mainly virulence factors, including a nuclease (nuc), a protease (splE) and a lipase (lip). As a consequence, extracellular nuclease, protease, and lipase activities were reduced in a ?yabJ-spoVG mutant. trans-complementation by SpoVG was sufficient to restore their reduced phenotypic expression and lowered transcription due to the yabJ-spoVG deletion. It did not restore, however, the changes triggered by ?(B) inactivation, indicating that both regulons only partially overlap, despite the ?(B) dependency of the yabJ-spoVG expression. Thus, ?(B) is likely to control additional, SpoVG-independent factors affecting the expression of numerous hydrolytic enzymes. SpoVG, on the other hand, seems to fine-tune the ?(B)-dependent regulation of a subset of virulence factors by antagonizing the ?(B) effect.

SUBMITTER: Schulthess B 

PROVIDER: S-EPMC3165683 | biostudies-literature | 2011 Sep

REPOSITORIES: biostudies-literature