8JO2
Structural basis of transcriptional activation by the OmpR/PhoB-family response regulator PmrA
Summary for 8JO2
| Entry DOI | 10.2210/pdb8jo2/pdb |
| EMDB information | 36453 |
| Descriptor | DNA (65-MER), DNA-directed RNA polymerase subunit alpha, DNA-directed RNA polymerase subunit beta, ... (8 entities in total) |
| Functional Keywords | pmra, rna polymerase, cryo-em, transcription |
| Biological source | Escherichia coli BL21(DE3) More |
| Total number of polymer chains | 10 |
| Total formula weight | 550996.69 |
| Authors | Lou, Y.-C.,Huang, H.-Y.,Chen, C.,Wu, K.-P. (deposition date: 2023-06-06, release date: 2023-08-30, Last modification date: 2023-10-25) |
| Primary citation | Lou, Y.C.,Huang, H.Y.,Yeh, H.H.,Chiang, W.H.,Chen, C.,Wu, K.P. Structural basis of transcriptional activation by the OmpR/PhoB-family response regulator PmrA. Nucleic Acids Res., 51:10049-10058, 2023 Cited by PubMed Abstract: 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. PubMed: 37665001DOI: 10.1093/nar/gkad724 PDB entries with the same primary citation |
| Experimental method | ELECTRON MICROSCOPY (2.74 Å) |
Structure validation
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