Mycobacterium tuberculosis RsdA provides a conformational rationale for selective regulation of σ-factor activity by proteolysis.

ABSTRACT: The relative levels of different σ factors dictate the expression profile of a bacterium. Extracytoplasmic function σ factors synchronize the transcriptional profile with environmental conditions. The cellular concentration of free extracytoplasmic function σ factors is regulated by the localization of this protein in a σ/anti-σ complex. Anti-σ factors are multi-domain proteins with a receptor to sense environmental stimuli and a conserved anti-σ domain (ASD) that binds a σ factor. Here we describe the structure of Mycobacterium tuberculosis anti-σ(D) (RsdA) in complex with the -35 promoter binding domain of σ(D) (σ(D)4). We note distinct conformational features that enable the release of σ(D) by the selective proteolysis of the ASD in RsdA. The structural and biochemical features of the σ

SUBMITTER: Jaiswal RK 

PROVIDER: S-EPMC3597663 | biostudies-literature | 2013 Mar

REPOSITORIES: biostudies-literature