Phages have adapted the same protein fold to fulfill multiple functions in virion assembly
Phages have adapted the same protein fold to fulfill multiple functions in virion assembly
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DOI：
10.1073/pnas.1005822107
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发表时间：
2010-08-10
影响因子：
11.1
通讯作者：
Davidson, Alan R.
中科院分区：
文献类型：
--
作者：
Cardarelli, Lia;Pell, Lisa G.;Davidson, Alan R.
进化关系可能存在于非常不同的蛋白质组之间，即使它们执行不同的功能并且显示很少的序列相似性。有尾噬菌体由于其巨大的多样性和保守的基因组结构，为鉴定这类群体提供了一个独特的可行系统。在这项工作中，我们使用结构，功能和基因组背景比较得出结论，头-尾连接蛋白和尾管蛋白的噬菌体λ偏离一个共同的祖先蛋白。三级和四级结构的进一步比较表明，噬菌体的底板枢纽和尾部终止子蛋白也可能是同一家族的一部分。我们认为，所有这些蛋白质都是从一个单一的祖先尾管蛋白折叠进化而来的，基因复制后的分化导致了今天在噬菌体中看到的这些蛋白质的特殊作用。虽然这种类型的进化机制已被提出用于其他系统，我们的工作提供了一组具有不同功能的蛋白质，不承担序列相似性的进化机制。我们的数据还表明，在λ头-尾连接器蛋白的N末端的结构元件的添加赋予它一个独特的蛋白质相互作用的能力相比，它的许多推定的同源物。
Evolutionary relationships may exist among very diverse groups of proteins even though they perform different functions and display little sequence similarity. The tailed bacteriophages present a uniquely amenable system for identifying such groups because of their huge diversity yet conserved genome structures. In this work, we used structural, functional, and genomic context comparisons to conclude that the head-tail connector protein and tail tube protein of bacteriophage lambda diverged from a common ancestral protein. Further comparisons of tertiary and quaternary structures indicate that the baseplate hub and tail terminator proteins of bacteriophage may also be part of this same family. We propose that all of these proteins evolved from a single ancestral tail tube protein fold, and that gene duplication followed by differentiation led to the specialized roles of these proteins seen in bacteriophages today. Although this type of evolutionary mechanism has been proposed for other systems, our work provides an evolutionary mechanism for a group of proteins with different functions that bear no sequence similarity. Our data also indicate that the addition of a structural element at the N terminus of the lambda head-tail connector protein endows it with a distinctive protein interaction capability compared with many of its putative homologues.