7v4e

Publication Abstract from PubMed

VpsR, the master regulator of biofilm formation in Vibrio cholerae, is an atypical NtrC1 type bEBP lacking residues essential for sigma(54)-RNAP binding and REC domain phosphorylation. Moreover, transcription from PvpsL, a promoter of biofilm biosynthesis, has been documented in presence of sigma(70)-RNAP/VpsR/c-di-GMP complex. It was proposed that c-di-GMP and VpsR together form an active transcription complex with sigma(70)-RNAP. However, the impact of c-di-GMP imparted on VpsR that leads to transcription activation with sigma(70)-RNAP remained elusive, largely due to the lack of the structure of VpsR and knowledge about c-di-GMP:VpsR interactions. In this direction we have solved the crystal structure of VpsR(RA), containing REC and AAA(+) domains, in apo, AMPPNP/GMPPNP and c-di-GMP bound states. Structures of VpsR(RA) unveiled distinctive REC domain orientation that leads to a novel dimeric association and noncanonical ATP/GTP binding. Moreover, we have demonstrated that at physiological pH VpsR remains as monomer having no ATPase activity but c-di-GMP imparted cooperativity to convert it to dimer with potent activity. Crystal structure of c-di-GMP:VpsR(RA) complex reveals that c-di-GMP binds near the C-terminal end of AAA(+) domain. Trp quenching studies on VpsR(R), VpsR(A), VpsR(RA), VpsR(AD) with c-di-GMP additionally demonstrated that c-di-GMP could potentially bind VpsR(D). We propose that c-di-GMP mediated tethering of VpsR(D) with VpsR(A) could likely favor generating the specific protein-DNA architecture for transcription activation.

Crystal Structure of VpsR Revealed Novel Dimeric Architecture and c-di-GMP Binding Site: Mechanistic Implications in Oligomerization, ATPase Activity and DNA Binding.,Chakrabortty T, Roy Chowdhury S, Ghosh B, Sen U J Mol Biol. 2022 Jan 30;434(2):167354. doi: 10.1016/j.jmb.2021.167354. Epub 2021 , Nov 10. PMID:34774564^[1]

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