诺如病毒CHN02/LZ35666株RdRp和VP1基因序列分析

诺如病毒（Noroviruses，NVs）为杯状病毒科的一个属，是引起人类病毒性胃肠炎暴发的重要病原。在美国、欧洲和日本，病毒性胃肠炎暴发中由NV引起的占93％。NV的基因组为单股正链RNA，全长约7．7kb，由3个开放阅读框（open reading frames，ORFs）组成，ORF1编码非结构蛋白，其中包括RNA聚合酶（RNA dependent RNA polymerase，RdRp），0RF2和0RF3分别编码主要（VP1）和次要（VP2）衣壳蛋白。VP1蛋白折叠成两个区域，壳区（Shell，S）和突出区（Protruding，P），S区形成内壳，P区形成拱样结构突出于内壳外。P区进一步分为P1和P2亚区，后者位于衣壳的最外面，P2区相对于S区和P1区序列高度变异，被认为是免疫识别和受体结合的关键部位。

Sequence Analysis of Norovirus CHN02/LZ35666 from Lanzhou City of China Based on RdRp and VP1 Genes

Sequence analysis of a new norovirus(NV) isolated from Lanzou city of China was performed based on partial sequence of RNA dependent RNA polymerase(RdRp) and complete capsid protein(VP1) gene.The isolated strain CHN02/LZ35666 shared high sequence homology with GII-4 NVs.Nucleotide homologies of RdRp region and encoded capsid protein region were 90.4%-98.6% and 89.8%-95.7%,respectively,while amino acid homology of capsid protein region was 94.4%-97.4%.The analysis of GDD motif in RdRp region indicated this GDD motif of Lanzhou strain differed from those of the GII-4 predominant epidemic strains.Lanzhou strain formed an independent branch in GII-4 cluster in the phylogenetic tree based on nucleotide sequence of RdRp region and amino acid sequence of capsid protein.Sequence alignment revealed a mutation at the fourth key site of the receptor-binding interface in the strains isolated after 2002 compared with those of previous strains suggesting a possible change of binding pattern to HBGAs receptors.