甘蓝型油菜SHR蛋白基因鉴定与结构分析

Identification and structural analysis of SHR genes in Brassica napus

植物SHR蛋白属于GRAS蛋白转录因子家族,保守羧基端含有VHIID结构域,氨基端不保守,参与调控植物物质合成和生长发育.参照拟南芥At SHR基因的CDS序列,采用生物信息学的方法在甘蓝型油菜数据库中鉴定出3个Bn SHR基因,进而分析其基因结构、生化特性、进化关系和蛋白结构.研究结果显示3个Bn SHR基因中有2个位于C基因组(来源于甘蓝)上,1个位于A基因组(来源于白菜);3个Bn SHR基因的氨基酸序列一致性为88.25%,与At SHR基因在进化上也高度同源,SHR基因在结构和功能上保守;亚细胞定位预测显示Bn SHR蛋白可能定位于过氧化物酶体,参与种子萌发过程中脂肪转变为糖分的过程;PHYRE2预测了Bn SHR蛋白的三级结构,由于序列的差异性导致了氨基末端处结构相差较大,但VHIID保守区结构类似,为β-折叠.

Plant SHR proteins belong to GRAS protein family of transcription factors,whose conservative C-terminus contains the VHIID domain, while the N-terminus are not conserved, play crucial role in biosynthesis and development regulation. To investigate the homologs in Brassica napus,3 Bn SHR genes in Brassica napus were identified through amino acid sequence of At SHR against Brassica Database,then analyzed their gene structure,biochemical characteristics,evolutionary relationships and protein structure. The results show that 2 Bn SHR locate in C genome from Brassica oleracea,1 Bn SHR locates in A genome from Brassica rapa; the consistency of this amino acid squences is 88. 25%,also have highly homology with At SHR in evolution,may result in the conserved functions; subcellular localization prediction of Bn SHR proteins are in peroxysome,may involve in transforming fat into sugar during the germination; the predicted tertiary structure of proteins display the architectural difference during N-terminus,otherwise,show the similar β-plated sheet with VHIID conserved region.