5msl

Publication Abstract from PubMed

Sporulation in Bacillus subtilis is governed by a cascade of alternative RNA polymerase sigma factors. We previously identified a small protein Fin that is produced under the control of the sporulation sigma factor sigmaF to create a negative feedback loop that inhibits sigmaF -directed gene transcription. Cells deleted for fin are defective for spore formation and exhibit increased levels of sigmaF -directed gene transcription. Based on pull-down experiments, chemical crosslinking, bacterial two-hybrid experiments and nuclear magnetic resonance chemical shift analysis, we now report that Fin binds to RNA polymerase and specifically to the coiled-coil region of the beta' subunit. The coiled-coil is a docking site for sigma factors on RNA polymerase, and evidence is presented that the binding of Fin and sigmaF to RNA polymerase is mutually exclusive. We propose that Fin functions by a mechanism distinct from that of classic sigma factor antagonists (anti-sigma factors), which bind directly to a target sigma factor to prevent its association with RNA polymerase, and instead functions to inhibit sigmaF by competing for binding to the beta' coiled-coil.

A novel RNA polymerase-binding protein that interacts with a sigma-factor docking site.,Wang Erickson AF, Deighan P, Chen S, Barrasso K, Garcia CP, Martinez-Lumbreras S, Alfano C, Krysztofinska EM, Thapaliya A, Camp AH, Isaacson RL, Hochschild A, Losick R Mol Microbiol. 2017 Aug;105(4):652-662. doi: 10.1111/mmi.13724. Epub 2017 Jun 19. PMID:28598017^[3]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.