The Saccharomyces cerevisiae Yta7 ATPase hexamer contains a unique bromodomain tier that functions in nucleosome disassembly.
The Saccharomyces cerevisiae Yta7 ATPase hexamer contains a unique bromodomain tier that functions in nucleosome disassembly.
复制标题
酿酒酵母YTA7 ATPase Hexamer包含一个独特的溴结构域层，可在核小体拆卸中起作用。
DOI：
10.1016/j.jbc.2022.102852
复制
发表时间：
2023-03
影响因子：
4.8
通讯作者：
Li, Huilin
中科院分区：
文献类型：
--
作者：
Wang, Feng;Feng, Xiang;He, Qing;Li, Hua;Li, Huilin
酿酒酵母Yta 7是一种染色质重塑剂，含有一个组蛋白相互作用的布罗莫结构域（BRD）和两个AAA+模块。Yta 7是如何识别组蛋白H3尾以促进核小体解体以进行DNA复制或RNA转录的，目前还不清楚。通过冷冻-EM分析，在这里，我们表明Yta 7组装一个三层六聚体，具有顶部BRD层、中间AAA 1层和底部AAA 2层。出乎意料的是，Yta 7 BRD稳定了大部分无序的N-末端区域的四链β-螺旋，称为BRD相互作用基序（BIM）。BIM基序是独特的面包酵母，我们表明BRD和BIM有助于核小体识别。我们发现Yta 7结合乙酰化和非乙酰化的H3肽，但对未修饰的肽具有更高的亲和力。这种性质与参与乙酰化肽识别的典型BRD的关键残基的缺乏和Yta 7在一般核小体重塑中的作用一致。有趣的是，BRD层以螺旋和平环形式存在于Yta 7 AAA+六聚体的顶部。螺旋可能处于核小体搜索模式，因为底部BRD阻止了AAA+室的入口。平环可能处于核小体解体状态，因为入口未被阻断，并且H3肽已进入AAA+室并被AAA 1孔环1和2稳定。事实上，我们表明，BRD层是一个平面环时，绑定到核小体。总的来说，我们的研究揭示了Yta 7的核小体解体。
The Saccharomyces cerevisiae Yta7 is a chromatin remodeler harboring a histone-interacting bromodomain (BRD) and two AAA+ modules. It is not well understood how Yta7 recognizes the histone H3 tail to promote nucleosome disassembly for DNA replication or RNA transcription. By cryo-EM analysis, here we show that Yta7 assembles a three-tiered hexamer with a top BRD tier, a middle AAA1 tier, and a bottom AAA2 tier. Unexpectedly, the Yta7 BRD stabilizes a four-stranded β-helix, termed BRD-interacting motif (BIM), of the largely disordered N-terminal region. The BIM motif is unique to the baker’s yeast, and we show both BRD and BIM contribute to nucleosome recognition. We found that Yta7 binds both acetylated and nonacetylated H3 peptides but with a higher affinity for the unmodified peptide. This property is consistent with the absence of key residues of canonical BRDs involved in acetylated peptide recognition and the role of Yta7 in general nucleosome remodeling. Interestingly, the BRD tier exists in a spiral and a flat-ring form on top of the Yta7 AAA+ hexamer. The spiral is likely in a nucleosome-searching mode because the bottom BRD blocks the entry to the AAA+ chamber. The flat ring may be in a nucleosome disassembly state because the entry is unblocked and the H3 peptide has entered the AAA+ chamber and is stabilized by the AAA1 pore loops 1 and 2. Indeed, we show that the BRD tier is a flat ring when bound to the nucleosome. Overall, our study sheds light on the nucleosome disassembly by Yta7.
登录
查看更多内容
影响因子：
48
作者：
Kucukelbir, Alp;Sigworth, Fred J.;Tagare, Hemant D.
通讯作者：
Tagare, Hemant D.
影响因子：
3.3
作者：
Bell SP;Labib K
通讯作者：
Labib K
影响因子：
13.8
作者：
Das, Chandrima;Tyler, Jessica K.;Churchill, Mair E. A.
通讯作者：
Churchill, Mair E. A.
影响因子：
64.8
作者：
Jumper J;Evans R;Pritzel A;Green T;Figurnov M;Ronneberger O;Tunyasuvunakool K;Bates R;Žídek A;Potapenko A;Bridgland A;Meyer C;Kohl SAA;Ballard AJ;Cowie A;Romera-Paredes B;Nikolov S;Jain R;Adler J;Back T;Petersen S;Reiman D;Clancy E;Zielinski M;Steinegger M;Pacholska M;Berghammer T;Bodenstein S;Silver D;Vinyals O;Senior AW;Kavukcuoglu K;Kohli P;Hassabis D
通讯作者：
Hassabis D
DOI：
10.1107/s0907444904019158
发表时间：
2004-12-01
影响因子：
2.2
作者：
Emsley, P;Cowtan, K
通讯作者：
Cowtan, K