Structure and dynamics of polymyxin-resistance-associated response regulator PmrA in complex with promoter DNA

• DOI: 10.1038/ncomms9838
• Publication Date: 2015-11-13T10:10:18Z
• Authors: Yuan-Chao Lou; Tsai-Hsuan Weng; Yi-Chuan Li; Yi-Fen Kao; Wei-Feng Lin; Hwei-Ling Peng; Shan-Ho Chou; Chwan-Deng Hsiao; Chinpan Chen
• Keywords: Response regulator; Transcription; Caulobacter crescentus

Abstract PmrA, an OmpR/PhoB family response regulator, manages genes for antibiotic resistance. Phosphorylation of regulator induces the formation a symmetric dimer in N-terminal receiver domain (REC), promoting two C-terminal DNA-binding domains (DBDs) to recognize promoter DNA elicit adaptive responses. Recently, determination KdpE–DNA complex structure revealed REC–DBD interface upstream protomer that may be necessary transcription activation. Here, we report 3.2-Å-resolution crystal PmrA–DNA complex, which reveals similar yet different interface. However, NMR studies show DNA-bound state, tumble separately and interaction is transiently populated solution. Reporter gene analyses PmrA variants with altered residues suggest not crucial supporting expression. We propose interdomain dynamics DBD–DBD help interact RNA polymerase holoenzyme activate downstream transcription.