葡萄血红蛋白的序列特征、结构建模及分子进化

Sequence Characterization,Structural Modeling,and Molecular Evolution of the Hemoglobin in Grapevine(Vitis vinifera)

对葡萄血红蛋白基因的结构、进化关系、序列特征及蛋白结构进行剖析。基因结构和蛋白序列特征分析表明:尽管葡萄3个血红蛋白基因外显子个数和保守基序组织结构变异较大,但功能结构域具有高度保守性。结构模拟显示,葡萄VvHb1以单体形式存在,而VvHb2和VvHb3则以二聚体形式存在,尽管它们三维构象以螺旋结构为主,但结合血红素分子活性不同。进化分析揭示,植物血红蛋白具有4个类群,其中葡萄的血红蛋白落入主要类群外,并且单独形成了一个进化分支,说明葡萄血红蛋白基因在物种形成后发生了快速进化和基因扩增现象。

In this study, a systematic analysis of grapevine hemoglobin including structure, phylogenetic relationship, sequence characterization, and protein structure, has been performed. Gene struc-ture and protein sequence analysis have shown that there is a great change in exon number and conserved motif organization, but a highly conservation in functional domain. Structural modeling showesthat the grapevine VvHbl is single chain, but VvHb2 and VvHb3 are dimer. They have the same basic components of helix but a distinct activity of binding to HEM ligand. Phylogenetic analysis has re-vealed four groups of plant hemoglobin, however three grapevine hemoglobins have not been classified into any group with an independent elade in evolutionary tree, indicating that hemoglobin gene hasbeen rapidly evolved and amplified after the formation of grapevine species.