中国西藏小反刍兽疫病毒野生株China/Tib/Gej/07-30基质蛋白基因和融合蛋白基因的分子特征分析

Sequence Analysis of the Matrix Protein and Fusion Protein Genes of a Field Peste des Petits Ruminants Virus Strain from Tibet,China

对我国西藏小反刍兽疫病毒野生株China/Tib/Gej/07-30进行基质蛋白(M)和融合蛋白(F)基因序列测定,并进行分子生物学特征分析。首先应用逆转录聚合酶链式反应扩增出M和F基因片段,对聚合酶链式反应产物进行直接测序,然后对测定的核苷酸和推测的氨基酸序列进行比较分析。China/Tib/Gej/07-30的M基因由1483个核苷酸组成,编码335个氨基酸,与其他分离株核苷酸和氨基酸序列同源性分别为92.4%～97.7%和97.0%～98.2%。F基因由2411个核苷酸组成,编码546个氨基酸,与其他分离株核苷酸和氨基酸序列同源性分别为85.5%～96.1%和94.3%～98.2%。China/Tib/Gej/07-30的F蛋白含有信号肽序列和跨膜结构域,序列高度变异。F蛋白第104～108位和第109～133位氨基酸位点分别是高度保守的裂解位点和融合肽结构域。F蛋白还含有序列高度保守的三个七肽重复区。China/Tib/Gej/07-30的M基因3′端的非编码区(UTR)长度为443个核苷酸,GC含量高达68.4%,与其他PPRV毒株的同源性为82.4%～93.5%。China/Tib/Gej/07-30的F基因5′UTR区长度为634个核苷酸,GC含量高达70.0%,与其他PPRV毒株序列相似性为76.2%～91.7%。

The nucleotide sequences of M and F genes from a field strain of peste des petits ruminants virus（PPRV）（＂China/Tib/Gej/07-30＂）was firstly determined.The M gene was 1 483 nucleotides in length with a single open reading frame（ORF）,encoding a protein of 335 amino acids.The F gene was 2411 nucleotides in length,encoding a protein of 546 amino acids.The resulting nucleotide sequence and the deduced amino acid sequences were compared with the homologous regions of other PPRV isolates.The nucleotide sequences of M and F genes of the ＂China/Tib/Gej/07-30＂ was 92.4%-97.7% and 85.5%-96.1% identical to other PPRV isolates,respectively,while a homology of 97.0%-98.2% and 94.3%-98.2% could be observed at the amino acids level respectively.Several sequence motifs in the M and F genes had been identified on the basis of conservation in the PPRVs and the morbilliviruses.The 3＇ untranslated region of M gene was 443 nucleotides in length with 82.4%-93.5% identical to other PPRV isolates.The 5＇ untranslated region of F gene was 634 nucleotides in length with 76.2%-91.7% identical to other PPRV isolates.