Vinogradov Serge N, Hoogewijs David, Bailly Xavier, Mizuguchi Kenji, Dewilde Sylvia, Moens Luc, Vanfleteren Jacques R
Department of Biochemistry and Molecular Biology, Wayne State University School of Medicine, Detroit, MI 48201, USA.
Gene. 2007 Aug 15;398(1-2):132-42. doi: 10.1016/j.gene.2007.02.041. Epub 2007 May 4.
Putative globins have been identified in 426 bacterial, 32 Archaeal and 67 eukaryote genomes. Among these sequences are the hitherto unsuspected presence of single domain sensor globins within Bacteria, Fungi, and a Euryarchaeote. Bayesian phylogenetic trees suggest that their occurrence in the latter two groups could be the result of lateral gene transfer from Bacteria. Iterated psiblast searches based on groups of globin sequences indicate that bacterial flavohemoglobins are closer to metazoan globins than to the other two lineages, the 2-over-2 globins and the globin-coupled sensors. Since Bacteria is the only kingdom to have all the subgroups of the three globin lineages, we propose a working model of globin evolution based on the assumption that all three lineages originated and evolved only in Bacteria. Although the 2-over-2 globins and the globin-coupled sensors recognize flavohemoglobins, there is little recognition between them. Thus, in the first stage of globin evolution, we favor a flavohemoglobin-like single domain protein as the ancestral globin. The next stage comprised the splitting off to single domain 2-over-2 and sensor-like globins, followed by the covalent addition of C-terminal domains resulting in the chimeric flavohemoglobins and globin-coupled sensors. The last stage encompassed the lateral gene transfers of some members of the three globin lineages to specific groups of Archaea and Eukaryotes.
在426个细菌、32个古菌和67个真核生物基因组中已鉴定出假定的珠蛋白。在这些序列中，细菌、真菌和一个广古菌中存在迄今未被怀疑的单结构域传感珠蛋白。贝叶斯系统发育树表明，它们在后两组中的出现可能是细菌横向基因转移的结果。基于珠蛋白序列组的迭代psiblast搜索表明，细菌黄素血红蛋白与后生动物珠蛋白的亲缘关系比与其他两个谱系（2-over-2珠蛋白和珠蛋白偶联传感器）更近。由于细菌是唯一拥有三种珠蛋白谱系所有亚组的界，我们基于所有三个谱系仅在细菌中起源和进化的假设，提出了一个珠蛋白进化的工作模型。尽管2-over-2珠蛋白和珠蛋白偶联传感器识别黄素血红蛋白，但它们之间几乎没有识别。因此，在珠蛋白进化的第一阶段，我们倾向于一种黄素血红蛋白样的单结构域蛋白作为祖先珠蛋白。下一阶段包括分裂成单结构域的2-over-2和传感器样珠蛋白，随后通过C末端结构域的共价添加产生嵌合黄素血红蛋白和珠蛋白偶联传感器。最后阶段包括三个珠蛋白谱系的一些成员横向基因转移到特定的古菌和真核生物群体。
