百合斑驳病毒云南分离物全基因组序列分析及CP结构预测

Sequencing and analysis of the genome of Lily mottle virus Yunnan isolates and structure prediction of their coat proteins

对云南嵩明百合上发生的百合斑驳病毒(Lily mottle virus,LMo V)进行全基因组序列测定及分析,并对LMo V嵩明分离物(LMo V-SMi1、LMo V-SMi2)和玉溪分离物(LMo V-YXi1、LMo V-YXi2)外壳蛋白(coat protein,CP)基因进行序列比较,发现云南的LMo V分为2个类群,玉溪分离物属于种群I,嵩明分离物属于种群II。2个类群间的核苷酸和氨基酸同源性分别为86.7%～89.5%、90.1%～92.7%,玉溪分离物和嵩明分离物相比,cp基因发生了3个核苷酸的缺失。对国内外LMo V所有分离物的cp基因氨基酸序列进行系统进化分析,结果表明所有LMo V分离物可划分为2个种群,种群I分离物较种群II分离物几乎均存在1个苏氨酸缺失的差异。此外,对LMo V-SMi2的CP相关特性和空间结构进行了初步预测,认为该蛋白为球状,具有较强的表面可能性,不存在跨膜区域,大多数区域能够形成主要的抗原决定簇,主要集中在aa12-22、aa31-42、aa83-99、aa179-191、aa215-223、aa249-259区段,可作为制备抗血清选择抗原的参考。LM o V-SM i2和LM o V-YXi1在二级结构和三级结构上存在一定的差异,但总体空间结构差异不大。

Complete sequence of one Lily mottle virus （LMoV） isolate which mainly infected lily from Song- ming county of Yunnan province was obtained and analyzed. Sequence comparison of coat protein （CP） gene among four LMoV isolates from Songming （LMoV-SMil, LMoV-SMi2 ） and Yuxi （LMoV-YXil, LMoV- YXi2） showed different identities at nucleotide and amino acid sequence levels, which could be divided into two subgroups, LMoV-YXil and LMoV-YXi2 belonged to subgroup I, while LMoV-SMil and LMoV-SMi2 be- longed to subgroup II. The two groups shared 86.7%-89.5% and 90.1%-92.7% identity at nucleotide and amino acid sequence levels, respectively. Sequence analysis of the cp gene revealed that there was a three-nucleotide deletion in the two Yuxi isolates compared with that of the two Songming isolates. Amino acid sequences com- parison of the cp gene of LMoV isolates available in GenBank showed that all of the isolates could be divided in- to two subgroups, and almost all of the isolates in subgroup I including a threonine deletion compared with thosein subgroup II. The results indicated that all of the analyzed LMoV isolates could be divided into two popula- tions. The related properties and spatial structure of the CP of LMoV-SMi2 were predicted, and the result showed that the CP of LMoV-SMi2 was spherical with great surface probability plot and no transmembrane domain was detected. The antigenic determinant mainly located at aa12-22, aa31-42, aa83-99, aa179-191, aa215-223, aa249- 259, and these regions could be used for antibody preparation. The CP spatial structure between LMoV-SMi2 and LMoV-YXil isolates were similar though there were some differences in their predicted CP secondary and tertiary structures.