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-Structure paper
Title | DNA looping mediates cooperative transcription activation. |
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Journal, issue, pages | Nat Struct Mol Biol, Vol. 31, Issue 2, Page 293-299, Year 2024 |
Publish date | Jan 4, 2024 |
Authors | Shu-Jing Han / Yong-Liang Jiang / Lin-Lin You / Li-Qiang Shen / Xiaoxian Wu / Feng Yang / Ning Cui / Wen-Wen Kong / Hui Sun / Ke Zhou / Hui-Chao Meng / Zhi-Peng Chen / Yuxing Chen / Yu Zhang / Cong-Zhao Zhou / |
PubMed Abstract | Transcription factors respond to multilevel stimuli and co-occupy promoter regions of target genes to activate RNA polymerase (RNAP) in a cooperative manner. To decipher the molecular mechanism, here ...Transcription factors respond to multilevel stimuli and co-occupy promoter regions of target genes to activate RNA polymerase (RNAP) in a cooperative manner. To decipher the molecular mechanism, here we report two cryo-electron microscopy structures of Anabaena transcription activation complexes (TACs): NtcA-TAC composed of RNAP holoenzyme, promoter and a global activator NtcA, and NtcA-NtcB-TAC comprising an extra context-specific regulator, NtcB. Structural analysis showed that NtcA binding makes the promoter DNA bend by ∼50°, which facilitates RNAP to contact NtcB at the distal upstream NtcB box. The sequential binding of NtcA and NtcB induces looping back of promoter DNA towards RNAP, enabling the assembly of a fully activated TAC bound with two activators. Together with biochemical assays, we propose a 'DNA looping' mechanism of cooperative transcription activation in bacteria. |
External links | Nat Struct Mol Biol / PubMed:38177666 |
Methods | EM (single particle) / X-ray diffraction |
Resolution | 2.35 - 7.6 Å |
Structure data | EMDB-34475, PDB-8h3v: EMDB-34476, PDB-8h40: EMDB-34477: Cryo-EM structure of the full transcription activation complex NtcA-NtcB-TAC focusing on NtcA and NtcB binding sites PDB-8h3z: |
Chemicals | ChemComp-IOD: ChemComp-HOH: |
Source |
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Keywords | TRANSCRIPTION / transcription activation complex / coordinated regulation / TRANSCRIPTION/DNA / LysR-type transcription factor / TRANSCRIPTION-DNA complex |