title: Nonstructural 5A gene variability of hepatitis C virus (HCV) during a 10-year follow up.
abstract: BACKGROUND
  Seven patients with chronic hepatitis C virus (HCV) infection were followed up for 10 years in order to analyze the molecular evolution of the HCV nonstructural 5A (NS5A) gene.
  
  
  METHODS
  Serum samples were obtained from seven patients with anti-HCV who were HCV-RNA positive. The HCV NS5A region, including the interferon sensitivity-determining region (ISDR), protein kinase R binding domain (PKR-BD), and V3 was amplified and cloned, and then sequenced. The nucleotide sequences of the region at the beginning and at the end of the 10 years were aligned with the CLUSTAL W program, version 1.8, and the corresponding amino-acid sequences were deduced.
  
  
  RESULTS
  The three serine residues at positions 2197, 2201, and 2204, suggested to be important for hyperphosphorylation of NS5A, were highly conserved in different patients and were within the quasispecies of each patient. The wild-type ISDR or minimally mutated strain was dominant in all the patients and the number of quasispecies decreased over time.
  
  
  CONCLUSIONS
  Our findings showed that the functional domains of NS5A were generally conserved over an interval of 10 years. Quasispecies distribution was variable and distinctly clustered over time during the natural course of HCV infection. These results may contribute to better understanding of HCV natural infection.
authors.affiliation: Department of Microbiology, School of Basic Medical Science, Peking University, Beijing 100083, China.
authors.forename: Wenmei
authors.initials: W
authors.lastname: Fan
authors.forename: Wanfu
authors.initials: W
authors.lastname: Zhu
authors.forename: Lai
authors.initials: L
authors.lastname: Wei
authors.forename: Qixin
authors.initials: Q
authors.lastname: Wang
authors.forename: Limin
authors.initials: L
authors.lastname: Yin
authors.forename: Shaocai
authors.initials: S
authors.lastname: Du
authors.forename: Hui
authors.initials: H
authors.lastname: Zhuang
mesh_terms: D000328:Adult; D000368:Aged; D000595:Amino Acid Sequence; D002681:China / Q000453:epidemiology; D005500:Follow-Up Studies; D014644:Genetic Variation / Q000235:genetics; D005838:Genotype; D016174:Hepacivirus / Q000235:genetics*; D019698:Hepatitis C, Chronic / Q000235:genetics / Q000821:virology; D006801:Humans; D008875:Middle Aged; D008969:Molecular Sequence Data; D010802:Phylogeny; D011446:Prospective Studies; D017361:Viral Nonstructural Proteins / Q000235:genetics*; D012324:RNA-Dependent RNA Polymerase
chemical_list: D017361:Viral Nonstructural Proteins; C087036:NS-5 protein, hepatitis C virus; D012324:RNA-Dependent RNA Polymerase