Gene duplication and gene conversion shape the evolution of archaeal chaperonins
Gene duplication and gene conversion shape the evolution of archaeal chaperonins
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DOI：
10.1006/jmbi.2002.5409
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发表时间：
2002-03-08
影响因子：
5.6
通讯作者：
Roger, AJ
中科院分区：
文献类型：
--
作者：
Archibald, JM;Roger, AJ
伴侣蛋白是一种多亚基双环复合物，介导新生或变性蛋白质的折叠。基因复制一直是一个强大的力量，在进化的伴侣蛋白在美洲。在这里，我们表明基因转换也是一个重要因素。我们利用了一种新的最大似然为基础的系统发育方法扫描DNA序列比对的异常系统发育信号的区域，如受基因转换。我们的研究结果表明，在crenarchaeotes，其中一个古老的基因复制产生α和β亚基发生在共同的祖先的Pyrodictium，Aeropyrum，Pyrobaculum和Sulfolobus谱系，多个独立的基因转换之间发生了独立的α和β基因在每个这些群体。值得注意的是，这些转换反复使编码底物结合结构域的基因区域均质化。这表明，虽然泉古菌中的α和β亚基仅共享50-60%的总体氨基酸序列同一性，但它们在底物结合中不具有不同的作用。远亲旁系同源物之间的隐藏基因转换可能比目前认识到的更常见，并且可能是在复制基因编码的蛋白质在复制后很长时间内减缓其功能分化的重要因素。(C)2002年爱思唯尔科学有限公司
Chaperonins are multi-subunit double-ring complexes that mediate the folding of nascent or denatured proteins. Gene duplication has been a potent force in the evolution of chaperonins in Archaea. Here we show that gene conversion has also been an important factor. We utilized a novel maximum likehood-based phylogenetic method for scanning DNA sequence alignments for regions of anomalous phylogenetic signal, such as those affected by gene conversion. Our results suggest that in crenarchaeotes, where an ancient gene duplication producing alpha and beta subunits took place in the common ancestor of the Pyrodictium, Aeropyrum, Pyrobaculum and Sulfolobus lineages, multiple independent gene conversions have occurred between the alpha and beta genes independently in each of these groups. Significantly, the conversions have repeatedly homogenized the region of the gene encoding the substrate-binding domain. This suggests that while the alpha and beta subunits in crenarchaeotes share only 50-60% overall amino acid sequence identity, they do not possess distinct roles in the binding of substrate. Cryptic gene conversion between distantly related paralogs may be more common than is currently appreciated, and could be a significant factor in slowing the functional differentiation of proteins encoded by duplicate genes long after their duplication. (C) 2002 Elsevier Science Ltd.