百脉根NIN旁系同源蛋白的结构歧异和功能分化  

Structural Divergence and Functional Differentiation in NIN Paralogous Proteins from Lotus japonicus

作　　者：朱新宇[1] 汪保华[1] 陈曹逸[1] 

机构地区：[1]南通大学生命科学学院,江苏南通226019

出　　处：《生物技术》2012年第4期41-46,共6页Biotechnology

基　　金：江苏省高校自然科学基金项目(No.09KJB180006);国家自然科学基金项目(No.31000729)资助

摘　　要：目的:研究百脉根(Lotus japonicus)NIN转录因子和它的旁系同源蛋白的结构歧异和功能分化。方法:从百脉根基因组中获取完全的NIN旁系同源蛋白质序列,通过生物信息学手段进行系统发育、理化性质、功能位点和蛋白质三级结构同源建模分析。结果:总共获得5个NIN旁系同源蛋白序列,其中2个属于新鉴别的成员,它们分属于两个不同的进化分支;脯氨酸含量在LjNLP3中比次高的LjNLP1增加33%,提示其具有耐旱的功能特征;功能位点分析显示NIN旁系同源蛋白之间存在差异,提示它们可能通过翻译后修饰发生了功能分化;LjNIN蛋白在进化过程中用一段α螺旋替代了LjNLP1的一段β折叠,这一差异可能导致百脉根Nin招募为根瘤感受基因。结论:初步揭示了百脉根NIN旁系同源蛋白的结构歧异与功能分化的关系,为进一步的实验研究奠定了基础。Objective:To study transcription factor NIN and its paralogous proteins in Lotus japonicus for their structural divergence and functional differentiation.Method:NIN paralogous proteins were obtained from Lotus japonicus genome.Bioinformatic approaches were used for investigating phylogeny,physicochemical property,functional site identification and homology modeling.Result:A total of five NIN paralogous proteins were obtained,and among them,two are newly recognized members,which belong to two different clusters;the proline content in LjNLP3 increased 33% than the second LjNLP1,indicating the possible characteristic of drought resistance;functional site analysis shows the discrepancy in five paralogous proteins,indicating that functional differentiations could have occurred by post-translational modifications;three-dimensional structural comparison between LjNIN and LjNLP1 reveals that a stretch of β-pleated sheet in LjNLP1 is displaced by a stretch of α-helix in LjNIN,which probably become the basis of Nin being recruited as nodule inception genes.Conclusion:A preliminary relationships between structural divergence and functional differentiation of Lotus japonicus NIN paralogous proteins were established,which lay the foundations for future experimental study.

关 键 词：百脉根 根瘤共生 NIN旁系同源蛋白 结构歧异 功能分化 

分 类 号：Q946[生物学—植物学]