Cohesin ATPase activities regulate DNA binding and coiled-coil configuration.
Cohesin ATPase activities regulate DNA binding and coiled-coil configuration.
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DOI：
10.1073/pnas.2208004119
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发表时间：
2022-08-16
影响因子：
11.1
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中科院分区：
文献类型：
--
作者：
黏连蛋白是由两个染色体结构维持（SMC）亚基和三个非SMC亚基组成的异五聚体蛋白复合物。两个SMC亚基形成异二聚体，其具有ATP酶头部和铰链，所述头部和铰链通过长卷曲螺旋连接。分离ATP酶突变体，然后全面鉴定SMC亚基中可以绕过ATP酶缺陷的抑制突变。突变等位基因的位置和性质反映了ATP酶活性如何受到结构适应的影响。ATP驱动的构象变化可以增强头部的DNA锚定，改变头部的卷曲螺旋与DNA通过的其他亚基的相互作用，并在中点附近的断裂位点附近折叠/延伸卷曲螺旋，以将彼此远离的DNA元件聚集在一起。粘着蛋白复合物是姐妹染色单体粘着和基因组紧密化所必需的。粘着蛋白卷曲螺旋（CC）可以在中点附近的断裂位点处折叠，以使位于卷曲螺旋的相对端的头部和铰链结构域接近。头部的ATP酶活性是否在这种构象变化中起作用尚不清楚。本文对粟酒裂殖酵母内粘蛋白ATP酶活性在内粘蛋白动力学中的作用进行了研究。分离和特性的粘着蛋白ATP酶温度敏感（TS）突变体表明，这两个ATP酶结构域所需的适当的染色体分离。自发抑制突变的无偏筛选拯救温度致死性的粘附素ATP酶突变体，确定了几个抑制热点的粘附素，位于ATP酶结构域之外。然后，我们针对这些抑制基因热点进行了全面的饱和诱变。大量的抑制突变表明了几种不同的方式来补偿ATP酶突变体：1）在卷曲螺旋中的中点附近的断裂位点处替换为具有较小侧链的氨基酸可以使卷曲螺旋更容易折叠和延伸：2）在头部的DNA结合区替换为精氨酸可以增强DNA结合;或3）取代卷曲螺旋中的疏水性氨基酸，连接头部并与其他亚基相互作用，可能会改变靠近头部的卷曲螺旋的构象。这些结果反映了一系列的结构变化的粘附素驱动的ATP酶活性可能包装DNA。
Cohesin is a heteropentameric protein complex consisting of two structural maintenance of chromosomes (SMC) subunits and three non-SMC subunits. The two SMC subunits form a heterodimer with an ATPase head and hinge that are connected by long coiled coils. Isolation of ATPase mutants followed by comprehensive identification of suppressor mutations in SMC subunits that can bypass ATPase defects was performed. Locations and properties of mutant alleles reflect how ATPase activities could be compromised by structural adaptation. ATP-driven conformational changes may enhance DNA anchoring by the head, alter interactions of coiled coils at the head with other subunits for DNA to go through, and fold/extend coiled coils near break sites around midpoint to bring together DNA elements far from each other. The cohesin complex is required for sister chromatid cohesion and genome compaction. Cohesin coiled coils (CCs) can fold at break sites near midpoints to bring head and hinge domains, located at opposite ends of coiled coils, into proximity. Whether ATPase activities in the head play a role in this conformational change is yet to be known. Here, we dissected functions of cohesin ATPase activities in cohesin dynamics in Schizosaccharomyces pombe. Isolation and characterization of cohesin ATPase temperature-sensitive (ts) mutants indicate that both ATPase domains are required for proper chromosome segregation. Unbiased screening of spontaneous suppressor mutations rescuing the temperature lethality of cohesin ATPase mutants identified several suppressor hotspots in cohesin that located outside of ATPase domains. Then, we performed comprehensive saturation mutagenesis targeted to these suppressor hotspots. Large numbers of the identified suppressor mutations indicated several different ways to compensate for the ATPase mutants: 1) Substitutions to amino acids with smaller side chains in coiled coils at break sites around midpoints may enable folding and extension of coiled coils more easily; 2) substitutions to arginine in the DNA binding region of the head may enhance DNA binding; or 3) substitutions to hydrophobic amino acids in coiled coils, connecting the head and interacting with other subunits, may alter conformation of coiled coils close to the head. These results reflect serial structural changes in cohesin driven by its ATPase activities potentially for packaging DNAs.
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影响因子：
16
作者：
Bürmann F;Funke LFH;Chin JW;Löwe J
通讯作者：
Löwe J
影响因子：
5.8
作者：
Delorenzi, M;Speed, T
通讯作者：
Speed, T
影响因子：
16
作者：
Haering, CH;Löwe, J;Nasmyth, K
通讯作者：
Nasmyth, K
影响因子：
16
作者：
Haering, CH;Schoffnegger, D;Löwe, J
通讯作者：
Löwe, J
影响因子：
16.6
作者：
Chao WC;Murayama Y;Muñoz S;Jones AW;Wade BO;Purkiss AG;Hu XW;Borg A;Snijders AP;Uhlmann F;Singleton MR
通讯作者：
Singleton MR