Moens L, Vanfleteren J, Van de Peer Y, Peeters K, Kapp O, Czeluzniak J, Goodman M, Blaxter M, Vinogradov S
Department of Biochemistry, University of Antwerp, Wilrijk, Belgium.
Mol Biol Evol. 1996 Feb;13(2):324-33. doi: 10.1093/oxfordjournals.molbev.a025592.
Using a new template based on an alignment of 145 nonvertebrate globins we examined several recently determined sequences of putative globins and globin-like hemeproteins. We propose that all globins have evolved from a family of ancestral, approx. 17-kDa hemeproteins, which displayed the globin fold and functioned as redox proteins. Once atmospheric O2 became available the acquisition of oxygen-binding properties was initiated, culminating in the various highly specialized functions known as present. During this evolutionary process, we suggest that (1) high oxygen affinity may have been acquired repeatedly and (2) the formation of chimeric proteins containing both a globin and a flavin binding domain was an additional and distinct evolutionary trend. Furthermore, globin-like hemeproteins encompass hemeproteins produced through convergent evolution from nonglobin ancestral proteins to carry out O2-binding functions as well as hemeproteins whose sequences exhibit the loss of some or all of the structural determinants of the globin fold. We also propose that there occurred two cases of horizontal globin gene transfer, one from an ancestor common to the ciliates Paramecium and Tetrahymena and the green alga Chlamydomonas to a cyanobacterium ancestor and the other, from a eukaryote ancestor of the yeasts Saccharomyces and Candida to a bacterial ancestor of the proteobacterial genera Escherichia, Alcaligenes, and Vitreoscilla.
我们使用基于145种非脊椎动物珠蛋白比对的新模板，研究了几种最近确定的假定珠蛋白和类珠蛋白血红素蛋白的序列。我们提出，所有珠蛋白都从一个祖先家族进化而来，该家族是约17 kDa的血红素蛋白，具有珠蛋白折叠结构并作为氧化还原蛋白发挥作用。一旦大气中的氧气可供利用，氧结合特性的获得就开始了，最终形成了目前已知的各种高度专业化的功能。在这个进化过程中，我们认为：(1) 高氧亲和力可能被多次获得；(2) 含有珠蛋白和黄素结合域的嵌合蛋白的形成是另一种独特的进化趋势。此外，类珠蛋白血红素蛋白包括通过从非珠蛋白祖先蛋白趋同进化产生的、执行氧结合功能的血红素蛋白，以及其序列显示出部分或全部珠蛋白折叠结构决定因素缺失的血红素蛋白。我们还提出发生了两例水平珠蛋白基因转移，一例是从纤毛虫草履虫和四膜虫以及绿藻衣藻的共同祖先转移到蓝细菌祖先，另一例是从酵母酿酒酵母和念珠菌的真核祖先转移到变形菌属大肠杆菌、产碱菌和透明颤菌的细菌祖先。
