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-Structure paper
タイトル | Structural basis of transcriptional activation by the OmpR/PhoB-family response regulator PmrA. |
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ジャーナル・号・ページ | Nucleic Acids Res, Vol. 51, Issue 18, Page 10049-10058, Year 2023 |
掲載日 | 2023年10月13日 |
![]() | Yuan-Chao Lou / Hsuan-Yu Huang / Hsin-Hong Yeh / Wei-Hung Chiang / Chinpan Chen / Kuen-Phon Wu / ![]() |
PubMed 要旨 | PmrA, an OmpR/PhoB-family response regulator, triggers gene transcription responsible for polymyxin resistance in bacteria by recognizing promoters where the canonical-35 element is replaced by the ...PmrA, an OmpR/PhoB-family response regulator, triggers gene transcription responsible for polymyxin resistance in bacteria by recognizing promoters where the canonical-35 element is replaced by the pmra-box, representing the PmrA recognition sequence. Here, we report a cryo-electron microscopy (cryo-EM) structure of a bacterial PmrA-dependent transcription activation complex (TAC) containing a PmrA dimer, an RNA polymerase σ70 holoenzyme (RNAPH) and the pbgP promoter DNA. Our structure reveals that the RNAPH mainly contacts the PmrA C-terminal DNA-binding domain (DBD) via electrostatic interactions and reorients the DBD three base pairs upstream of the pmra-box, resulting in a dynamic TAC conformation. In vivo assays show that the substitution of the DNA-recognition residue eliminated its transcriptional activity, while variants with altered RNAPH-interacting residues resulted in enhanced transcriptional activity. Our findings suggest that both PmrA recognition-induced DNA distortion and PmrA promoter escape play crucial roles in its transcriptional activation. |
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手法 | EM (単粒子) |
解像度 | 2.74 Å |
構造データ | EMDB-36453, PDB-8jo2: |
由来 |
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![]() | TRANSCRIPTION / PmrA / RNA polymerase / cryo-EM |