ジャーナル: J Mol Biol / 年: 2013 タイトル: Structural insights into transcriptional repression by noncoding RNAs that bind to human Pol II. 著者: Susanne A Kassube / Jie Fang / Patricia Grob / Petro Yakovchuk / James A Goodrich / Eva Nogales / 要旨: Gene transcription is regulated in response to environmental changes and developmental cues. In mammalian cells subjected to stress conditions such as heat shock, transcription of most protein-coding ...Gene transcription is regulated in response to environmental changes and developmental cues. In mammalian cells subjected to stress conditions such as heat shock, transcription of most protein-coding genes decreases, while the transcription of heat shock protein genes increases. Repression involves direct binding to RNA polymerase II (Pol II) of certain noncoding RNAs (ncRNAs) that are upregulated upon heat shock. Another class of ncRNAs is also upregulated and binds to Pol II but does not inhibit transcription. Incorporation of repressive ncRNAs into pre-initiation complexes prevents transcription initiation, while non-repressive ncRNAs are displaced from Pol II by TFIIF. Here, we present cryo-electron microscopy reconstructions of human Pol II in complex with six different ncRNAs from mouse and human. Our structures show that both repressive and non-repressive ncRNAs bind to a conserved binding site within the cleft of Pol II. The site, which is also shared with a previously characterized yeast aptamer, is close to the active center and, thus, in an ideal position to regulate transcription. Importantly, additional RNA elements extend flexibly beyond the docking site. We propose that the differences concerning the repressive activity of the ncRNAs analyzed must be due to the distinct character of these more unstructured, flexible segments of the RNA that emanate from the cleft.
全体 : human RNA polymerase II in complex with B2 RNA
全体
名称: human RNA polymerase II in complex with B2 RNA
要素
試料: human RNA polymerase II in complex with B2 RNA
タンパク質・ペプチド: Rpb12
タンパク質・ペプチド: Rpb11
タンパク質・ペプチド: Rpb10
タンパク質・ペプチド: Rpb9
タンパク質・ペプチド: Rpb8
タンパク質・ペプチド: Rpb7
タンパク質・ペプチド: Rpb6
タンパク質・ペプチド: Rpb5
タンパク質・ペプチド: Rpb4
タンパク質・ペプチド: Rpb3
タンパク質・ペプチド: Rpb2
タンパク質・ペプチド: Rpb1
RNA: B2 RNA
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超分子 #1000: human RNA polymerase II in complex with B2 RNA
超分子
名称: human RNA polymerase II in complex with B2 RNA / タイプ: sample / ID: 1000 集合状態: RNA polymerase II (12 polypeptide chains) binds to B2 RNA Number unique components: 13
想定した対称性 - 点群: C1 (非対称) / アルゴリズム: OTHER / 解像度のタイプ: BY AUTHOR / 解像度: 25.0 Å / 解像度の算出法: FSC 0.5 CUT-OFF / ソフトウェア - 名称: EMAN2, FREALIGN 詳細: Projection matching using a low-pass filtered model of apo Pol II as the starting model 使用した粒子像数: 15814