Mechanisms of DNA opening revealed in AAA+ transcription complex structures.
Mechanisms of DNA opening revealed in AAA+ transcription complex structures.
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DOI：
10.1126/sciadv.add3479
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发表时间：
2022-12-21
期刊：
影响因子：
13.6
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中科院分区：
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Gene transcription is carried out by RNA polymerase (RNAP) and requires the conversion of the initial closed promoter complex, where DNA is double stranded, to a transcription-competent open promoter complex, where DNA is opened up. In bacteria, RNAP relies on σ factors for its promoter specificities. Using a special form of sigma factor (σ54), which forms a stable closed complex and requires its activator that belongs to the AAA+ ATPases (ATPases associated with diverse cellular activities), we obtained cryo–electron microscopy structures of transcription initiation complexes that reveal a previously unidentified process of DNA melting opening. The σ54 amino terminus threads through the locally opened up DNA and then becomes enclosed by the AAA+ hexameric ring in the activator-bound intermediate complex. Our structures suggest how ATP hydrolysis by the AAA+ activator could remove the σ54 inhibition while helping to open up DNA, using σ54 amino-terminal peptide as a pry bar. cryoEM structures reveal DNA opening by a protein peptide threading through the DNA double helix in transcription initiation.
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DOI：
10.1107/s2059798318006551
发表时间：
2018-06-01
期刊：
Acta crystallographica. Section D, Structural biology
影响因子：
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作者：
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通讯作者：
Adams PD
影响因子：
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作者：
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影响因子：
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Buck M
影响因子：
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Casaz, P;Gallegos, MT;Buck, M
通讯作者：
Buck, M
DOI：
10.1107/s0907444910007493
发表时间：
2010-04
期刊：
Acta crystallographica. Section D, Biological crystallography
影响因子：
--
作者：
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Cowtan K