National Natural Science Foundation of China (NSFC)
32171198
中国
Ministry of Science and Technology (MoST, China)
2018YFA090070
中国
引用
ジャーナル: Nat Struct Mol Biol / 年: 2024 タイトル: DNA looping mediates cooperative transcription activation. 著者: 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 / 要旨: 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.