Bashton Matthew, Chothia Cyrus
MRC Laboratory of Molecular Biology, Hills Road, Cambridge, CB2 2QH, United Kingdom.
Structure. 2007 Jan;15(1):85-99. doi: 10.1016/j.str.2006.11.009.
During evolution, many new proteins have been formed by the process of gene duplication and combination. The genes involved in this process usually code for whole domains. Small proteins contain one domain; medium and large proteins contain two or more domains. We have compared homologous domains that occur in both one-domain proteins and multidomain proteins. We have determined (1) how the functions of the individual domains in the multidomain proteins combine to produce their overall functions and (2) the extent to which these functions are similar to those in the one-domain homologs. We describe how domain combinations increase the specificity of enzymes; act as links between domains that have functional roles; regulate activity; combine within one chain functions that can act either independently, in concert or in new contexts; and provide the structural framework for the evolution of entirely new functions.
在进化过程中，许多新蛋白质是通过基因复制和组合过程形成的。参与此过程的基因通常编码完整的结构域。小蛋白质包含一个结构域；中等和大蛋白质包含两个或更多结构域。我们比较了单结构域蛋白质和多结构域蛋白质中都存在的同源结构域。我们确定了：（1）多结构域蛋白质中各个结构域的功能如何结合以产生其整体功能；（2）这些功能与单结构域同源物中的功能相似的程度。我们描述了结构域组合如何提高酶的特异性；充当具有功能作用的结构域之间的连接；调节活性；在一条链内组合可以独立、协同或在新环境中起作用的功能；并为全新功能的进化提供结构框架。
