6P1K
Cryo-EM structure of Escherichia coli sigma70 bound RNAP polymerase holoenzyme
Summary for 6P1K
| Entry DOI | 10.2210/pdb6p1k/pdb |
| EMDB information | 20230 |
| Descriptor | DNA-directed RNA polymerase subunit alpha, DNA-directed RNA polymerase subunit beta, DNA-directed RNA polymerase subunit beta', ... (7 entities in total) |
| Functional Keywords | protein-dna complex, transcription initiation, rna polyermase, dna promoter melting, transcription |
| Biological source | Escherichia coli More |
| Total number of polymer chains | 6 |
| Total formula weight | 463132.12 |
| Authors | Chen, J.,Chiu, C.E.,Campbell, E.A.,Darst, S.A. (deposition date: 2019-05-20, release date: 2020-02-26, Last modification date: 2024-03-13) |
| Primary citation | Chen, J.,Gopalkrishnan, S.,Chiu, C.,Chen, A.Y.,Campbell, E.A.,Gourse, R.L.,Ross, W.,Darst, S.A. E. coliTraR allosterically regulates transcription initiation by altering RNA polymerase conformation. Elife, 8:-, 2019 Cited by PubMed Abstract: TraR and its homolog DksA are bacterial proteins that regulate transcription initiation by binding directly to RNA polymerase (RNAP) rather than to promoter DNA. Effects of TraR mimic the combined effects of DksA and its cofactor ppGpp, but the structural basis for regulation by these factors remains unclear. Here, we use cryo-electron microscopy to determine structures of RNAP, with or without TraR, and of an RNAP-promoter complex. TraR binding induced RNAP conformational changes not seen in previous crystallographic analyses, and a quantitative analysis revealed TraR-induced changes in RNAP conformational heterogeneity. These changes involve mobile regions of RNAP affecting promoter DNA interactions, including the βlobe, the clamp, the bridge helix, and several lineage-specific insertions. Using mutational approaches, we show that these structural changes, as well as effects on σ region 1.1, are critical for transcription activation or inhibition, depending on the kinetic features of regulated promoters. PubMed: 31841111DOI: 10.7554/eLife.49375 PDB entries with the same primary citation |
| Experimental method | ELECTRON MICROSCOPY (4.05 Å) |
Structure validation
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