Crystal structure of a Flp recombinase-Holliday junction complex: Assembly of an active oligomer by helix swapping
Crystal structure of a Flp recombinase-Holliday junction complex: Assembly of an active oligomer by helix swapping
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DOI：
10.1016/s1097-2765(00)00086-1
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发表时间：
2000-10-01
期刊：
影响因子：
16
通讯作者：
Rice, PA
中科院分区：
文献类型：
--
作者：
Chen, Y;Narendra, U;Rice, PA
已在2.65埃分辨率下确定了与霍利迪连接中间体结合的Flp重组酶四聚体的晶体结构。Flp的两个结构域中只有一个包含活性位点，它在结构上与其他λ整合酶家族的位点特异性重组酶（如Ore）相关。然而，Flp活性位点的不同之处在于，含有亲核酪氨酸的螺旋发生了结构域交换，因此它以反式切割其DNA靶标。Flp四聚体呈现出与方形平面霍利迪连接底物相匹配的伪四重对称性。这种四聚体通过单体之间额外的新型反式相互作用而稳定。该结构阐明了在一个酶家族中，如何在化学水平上保持机制的统一性，同时在结构水平上允许有显著的差异。
The crystal structure of a Flp recombinase tetramer bound to a Holliday junction intermediate has been determined at 2.65 Angstrom resolution. Only one of Flp's two domains, containing the active site, is structurally related to other lambda integrase family site-specific recombinases, such as Ore. The Flp active site differs, however, in that the helix containing the nucleophilic tyrosine is domain swapped, such that it cuts its DNA target in trans. The Flp tetramer displays pseudo fourfold symmetry matching that of the square planar Holliday junction substrate. This tetramer is stabilized by additional novel trans interactions among monomers. The structure illustrates how mechanistic unity is maintained on a chemical level while allowing for substantial variation on the structural level within a family of enzymes.