All in the family: Structural and evolutionary relationships among three modular proteins with diverse functions and variable assembly
All in the family: Structural and evolutionary relationships among three modular proteins with diverse functions and variable assembly
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DOI：
10.1002/pro.5560070801
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发表时间：
1998-08-01
期刊：
影响因子：
8
通讯作者：
Bolin, JT
中科院分区：
文献类型：
--
作者：
Bergdoll, M;Eltis, LD;Bolin, JT
分析了三种功能不同且序列相似性较低的蛋白质的晶体结构，以评估结构和进化关系。这些蛋白质包括细菌博来霉素抗性蛋白、细菌外二醇双加氧酶和人乙二醛酶 I。结构比较以及系统发育分析强烈表明，这些结构所代表的现代蛋白质家族是通过丰富的进化历史产生的，其中包括多个基因复制和融合事件。这些事件在某些情况下似乎在历史上是共同的，但在其他情况下是平行且历史上独立的。一个重要的早期事件被认为是在第一次基因融合之前在寡聚祖先中建立金属结合。观察到同源模块空间排列的变化，这与三维域交换的结构原理一致，但在从较小的二聚体或四聚体形成较大单体的不寻常背景下。这些比较支持金属蛋白进化的一般机制，该机制利用同源寡聚蛋白的对称性来产生金属结合位点，并依赖于基因复制所实现的对称性松弛来建立和完善特定功能。
The crystal structures of three proteins of diverse function and low sequence similarity were analyzed to evaluate structural and evolutionary relationships. The proteins include a bacterial bleomycin resistance protein, a bacterial extradiol dioxygenase, and human glyoxalase I. Structural comparisons, as well as phylogenetic analyses, strongly indicate that the modem family of proteins represented by these structures arose through a rich evolutionary history that includes multiple gene duplication and fusion events. These events appear to be historically shared in some cases, but parallel and historically independent in others. A significant early event is proposed to be the establishment of metal-binding in an oligomeric ancestor prior to the first gene fusion. Variations in the spatial arrangements of homologous modules are observed that are consistent with the structural principles of three-dimensional domain swapping, but in the unusual context of the formation of larger monomers from smaller dimers or tetramers. The comparisons support a general mechanism for metalloprotein evolution that exploits the symmetry of a homooligomeric protein to originate a metal binding site and relies upon the relaxation of symmetry, as enabled by gene duplication, to establish and refine specific functions.