Présentation
Regulation of many key biological processes in bacteria involves the interplay between Sigma factors and anti-Sigma factors that typically attenuate Sigma factor function by restricting its access to RNA polymerase (RNAP). In contrast, our studies demonstrated that the small protein Crl regulates SigmaS activity by a unique mechanism, forming a transient complex with SigmaS whereby it increases SigmaS affinity for the core RNAP. We took advantage of our finding that crl is less widespread and less conserved at the sequence level than rpoS to identify the structural determinants of the Crl-SigmaS interaction, using well-integrated structural, functional, biophysical and molecular modeling approaches, as part of the ANR project SIGMADAPT coordinated by F. Norel.
