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.
