Selectivity among Anti-σ Factors by Mycobacterium tuberculosis ClpX Influences Intracellular Levels of Extracytoplasmic Function σ Factors.

ABSTRACT: Extracytoplasmic function σ factors that are stress inducible are often sequestered in an inactive complex with a membrane-associated anti-σ factor. Mycobacterium tuberculosis membrane-associated anti-σ factors have a small, stable RNA gene A (ssrA)-like degron for targeted proteolysis. Interaction between the unfoldase, ClpX, and a substrate with an accessible degron initiates energy-dependent proteolysis. Four anti-σ factors with a mutation in the degron provided a set of natural substrates to evaluate the influence of the degron on degradation strength in ClpX-substrate processivity. We note that a point mutation in the degron (X-Ala-Ala) leads to an order-of-magnitude difference in the dwell time of the substrate on ClpX. Differences in ClpX/anti-σ interactions were corre

SUBMITTER: Joshi AC 

PROVIDER: S-EPMC6398269 | biostudies-literature | 2019 Mar

REPOSITORIES: biostudies-literature