title: [Variability analysis of S2 gene of SARS-CoV].
abstract: OBJECTIVE
  To determine the sequence of S2 gene of SARS-associated coronavirus (SARS-CoV) GD322 and analyze the phyletic evolution of S2 gene.
  
  
  METHODS
  S2 gene fragment was amplified from SARS-CoV GD322 genome with RT-PCR and ligated to pGEM-T vector for sequence analysis after transformation of the plasmid into E. coli DH5a. The variability of S2 genes and S2 proteins from 12 strains isolated in the early, intermediate and advanced stages of the SARS outbreak were analyzed and the phylogenetic tree was constructed with Lasergene, Clustal X, DNAman and Treeview. T cell antigen epitopes of S2 protein were predicted on the basis of Internet database.
  
  
  RESULTS
  With the epidemic spread of SARS-CoV, the S2 genes of the virus tended to become stable. Homology of S2 genes of SARS-CoV isolated in advanced stage of the outbreak reached 99.9%. Prediction of T cell antigen epitope showed that mutation at the 57th amino acid effected T cell antigen epitope.
  
  
  CONCLUSIONS
  S2 gene of GD322 SARS-CoV is relatively stable during the epidemic spread of the virus, and mutation at the 57th amino acids of S2 protein may affect the T cell antigen epitope.
authors.affiliation: Department of Microbiology, Southern Medical University, Guangzhou 510515, China. zhou_hao120@ 163.com
authors.forename: Hao
authors.initials: H
authors.lastname: Zhou
authors.forename: Bei-guo
authors.initials: BG
authors.lastname: Long
authors.forename: Wen-bing
authors.initials: WB
authors.lastname: Zhang
authors.forename: Li-fang
authors.initials: LF
authors.lastname: Jiang
authors.forename: Li-dan
authors.initials: LD
authors.lastname: Chen
authors.forename: Shu-ji
authors.initials: SJ
authors.lastname: Gong
authors.forename: Wei
authors.initials: W
authors.lastname: Zhao
mesh_terms: D004926:Escherichia coli / Q000235:genetics; D014644:Genetic Variation; D006801:Humans; D010802:Phylogeny; D017354:Point Mutation; D045473:Severe acute respiratory syndrome-related coronavirus / Q000235:genetics* / Q000302:isolation & purification; D017422:Sequence Analysis, DNA; D045169:Severe Acute Respiratory Syndrome / Q000821:virology; D014759:Viral Envelope Proteins / Q000235:genetics*
chemical_list: D014759:Viral Envelope Proteins