苦楝丛枝植原体相关膜蛋白基因分析及结构预测  

Sequence Analysis and Structure Prediction of Membrane-associated Protein Genes of Chinaberry Witches’-broom Phytoplasma

作　　者：吴德喜[1] 袁恩平[1] 王连春[1] 蔡红[1] 陈海如[1] 

机构地区：[1]云南农业大学,云南省植物病理重点实验室,云南昆明650201

出　　处：《云南农业大学学报（自然科学版）》2013年第3期310-316,共7页Journal of Yunnan Agricultural University:Natural Science

基　　金：国家自然科学基金(31060239);云南省科技创新人才计划项目(2011HB026)

摘　　要：根据植原体编码蛋白转运系统SecY亚基以及抗原膜蛋白amp基因的保守序列分别设计引物,并采用PCR对采自云南文山的苦楝丛枝感病植株总DNA进行扩增、产物克隆及序列测定。结果显示扩增的SecY亚基DNA片段长1 354 bp,编码一个包含414个氨基酸的SecY蛋白,序列同源性显示该片段与"Ca.Phytoplas-ma asteris"(16SrI组)中的株系最高,达94%～99%;构建16SrI组内基于secY序列的系统进化树,认为该株系为secY(I)-O亚组。扩增的免疫膜蛋白DNA片段长1 176 bp,编码1个包含233个氨基酸的免疫膜蛋白(Amp)。蛋白结构预测显示secY亚基蛋白是一个有9个跨膜区的整合跨膜蛋白,而Amp蛋白是一类两端具有明显跨膜区,且N-端有多肽切割位点的Ⅲ型膜蛋白。Primers were designed based on the conserved regions of 2 membrane protein genes and were used to amplify the 2 genes of Phytoplasm by PCR from total DNA of diseased chinaberry plants showing witches-broom （CbWB-Wsh） collected in Wenshan county of Yunnan Province. The genes secY and amp, encoding the protein translocase subunit SecY, and the antigenic membrane protein Amp, respectively, were cloned and completely sequenced. The amplified secY DNA fragment was 1 354 bp in length, encoding a secY protein of 414 amino acids. Homology analysis showed that secY gene of CbWB-Wsh was high homology （94% -99% ） with those of strains classified in ＇Ca. Phyto- plasma asteris＇ （group 16SrI）. From the dendrogram based on the secY gene sequences of group 16SrI, indicated that the CbWB-Wsh was classified into subgroup O, group secY （I）. The amplified amp fragment was 1 176 bp in length, encoding an antigenic membrane protein of 233 amino acids. Prediction of protein structure showed that the subunit secY has 9 evident transmembrane domains. The Amp protein has two transmembrane regions in N-terminal and C-terminal, respectively, and classified in membrane protein type III, which had a cleavage site of signal peptide in the N-terminal.

关 键 词：苦楝丛枝植原体 膜蛋白 SECY AMP 结构预测 

分 类 号：S718.87[农业科学—林学]