National Institutes of Health/National Cancer Institute (NIH/NCI)
GM041376
米国
引用
ジャーナル: Proc Natl Acad Sci U S A / 年: 2022 タイトル: In transcription antitermination by Qλ, NusA induces refolding of Qλ to form a nozzle that extends the RNA polymerase RNA-exit channel. 著者: Zhou Yin / Jeremy G Bird / Jason T Kaelber / Bryce E Nickels / Richard H Ebright / 要旨: Lambdoid bacteriophage Q proteins are transcription antipausing and antitermination factors that enable RNA polymerase (RNAP) to read through pause and termination sites. Q proteins load onto RNAP ...Lambdoid bacteriophage Q proteins are transcription antipausing and antitermination factors that enable RNA polymerase (RNAP) to read through pause and termination sites. Q proteins load onto RNAP engaged in promoter-proximal pausing at a Q binding element (QBE) and adjacent sigma-dependent pause element to yield a Q-loading complex, and they translocate with RNAP as a pausing-deficient, termination-deficient Q-loaded complex. In previous work, we showed that the Q protein of bacteriophage 21 (Q21) functions by forming a nozzle that narrows and extends the RNAP RNA-exit channel, preventing formation of pause and termination RNA hairpins. Here, we report atomic structures of four states on the pathway of antitermination by the Q protein of bacteriophage λ (Qλ), a Q protein that shows no sequence similarity to Q21 and that, unlike Q21, requires the transcription elongation factor NusA for efficient antipausing and antitermination. We report structures of Qλ, the Qλ-QBE complex, the NusA-free pre-engaged Qλ-loading complex, and the NusA-containing engaged Qλ-loading complex. The results show that Qλ, like Q21, forms a nozzle that narrows and extends the RNAP RNA-exit channel, preventing formation of RNA hairpins. However, the results show that Qλ has no three-dimensional structural similarity to Q21, employs a different mechanism of QBE recognition than Q21, and employs a more complex process for loading onto RNAP than Q21, involving recruitment of Qλ to form a pre-engaged loading complex, followed by NusA-facilitated refolding of Qλ to form an engaged loading complex. The results establish that Qλ and Q21 are not structural homologs and are solely functional analogs.
履歴
登録
2022年3月15日
登録サイト: RCSB / 処理サイト: RCSB
改定 1.0
2022年9月28日
Provider: repository / タイプ: Initial release
改定 1.1
2024年5月22日
Group: Data collection / カテゴリ: chem_comp_atom / chem_comp_bond
#241 - 2020年1月 20年の分子を振り返って (Twenty Years of Molecules) 類似性 (1)
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集合体
登録構造単位
A: Antitermination protein Q B: DNA (5'-D(P*CP*AP*CP*CP*CP*AP*AP*TP*TP*TP*TP*AP*TP*TP*CP*AP*AP*TP*G)-3') C: DNA (5'-D(P*CP*AP*TP*TP*GP*AP*AP*TP*AP*AP*AP*AP*TP*TP*GP*GP*GP*TP*G)-3') ヘテロ分子