Regulatory mutations in Sin recombinase support a structure-based model of the synaptosome.
Regulatory mutations in Sin recombinase support a structure-based model of the synaptosome.
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DOI：
10.1111/j.1365-2958.2009.06756.x
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发表时间：
2009-10
影响因子：
3.6
通讯作者：
Stark WM
中科院分区：
文献类型：
--
作者：
Rowland SJ;Boocock MR;McPherson AL;Mouw KW;Rice PA;Stark WM
解离酶Sin通过组装包含催化和调节Sin四聚体和建筑DNA弯曲蛋白的精心制作的缠绕突触体来调节DNA链交换。最近解决了调节四聚体的晶体结构，为调节的结构基础提供了新的见解。在这里，我们描述的选择和表征的两个类的辛突变，分别绕过或破坏的功能的监管四聚体。在N-末端结构域中约20%的残基处发现了激活突变，其允许催化四聚体在位点I（交叉位点）独立地组装和发挥功能。最强烈的激活突变（Q115 R）稳定了催化活性的突触四聚体在体外。这些突变的位置表明，它们通过使基态位点I结合的二聚体的构象不稳定，或通过稳定活性催化四聚体的改变的构象来起作用。阻断调节四聚体激活的突变仅映射到两个残基，F52和R54，支持先前报道的晶体二聚体-二聚体界面的功能作用。我们建议如何F52/R54之间的接触调节和催化亚基可能会促进组装的活性催化四聚体内的突触体。
The resolvase Sin regulates DNA strand exchange by assembling an elaborate interwound synaptosome containing catalytic and regulatory Sin tetramers, and an architectural DNA-bending protein. The crystal structure of the regulatory tetramer was recently solved, providing new insights into the structural basis for regulation. Here we describe the selection and characterization of two classes of Sin mutations that, respectively, bypass or disrupt the functions of the regulatory tetramer. Activating mutations, which allow the catalytic tetramer to assemble and function independently at site I (the crossover site), were found at ∼20% of residues in the N-terminal domain. The most strongly activating mutation (Q115R) stabilized a catalytically active synaptic tetramer in vitro. The positions of these mutations suggest that they act by destabilizing the conformation of the ground-state site I-bound dimers, or by stabilizing the altered conformation of the active catalytic tetramer. Mutations that block activation by the regulatory tetramer mapped to just two residues, F52 and R54, supporting a functional role for a previously reported crystallographic dimer–dimer interface. We suggest how F52/R54 contacts between regulatory and catalytic subunits might promote assembly of the active catalytic tetramer within the synaptosome.
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影响因子：
14.9
作者：
Olorunniji FJ;He J;Wenwieser SV;Boocock MR;Stark WM
通讯作者：
Stark WM
影响因子：
16
作者：
Mouw, Kent W.;Rowland, Sally-J.;Gajjar, Mark M.;Boocock, Martin R.;Stark, W. Marshall;Rice, Phoebe A.
通讯作者：
Rice, Phoebe A.
影响因子：
11.4
作者：
RICE, PA;STEITZ, TA
通讯作者：
STEITZ, TA
影响因子：
3.6
作者：
Rowland, SJ;Boocock, MR;Stark, WM
通讯作者：
Stark, WM
影响因子：
64.5
作者：
KRASNOW, MA;COZZARELLI, NR
通讯作者：
COZZARELLI, NR