title: [Variation of primary structure in nonstructural region 5 b of hepatitis C virus].
abstract: OBJECTIVE
  To analyze the sequence variation in the nonstructural region 5 b(NS5 b) of hepatitis C virus (HCV) of China.
  
  
  METHODS
  Complementary DNA fragments from sera of 49 Chinese patients were amplified by reverse transcription nested polymerase chain reaction (RT-nested-PCR) and the products were cloned and sequenced.
  
  
  RESULTS
  33 clones belonged to genotype 1 b and 16 clones were genotype 2 a. Several conserved nucleotide sites were found to be different from those of Japanese isolates though they belonged to an identical genotype. Comparison of average homology among the 33 clones of genotype 1 b and the 16 clones of genotype 2 a indicated that the average homology among genotype 2 a was lower than that among genotype 1 b. A deletion of three nucleotides and a frame-shift, resulting from the introduction of an in-frame stop codon, were firstly observed in the NS5 b region.
  
  
  CONCLUSIONS
  The nucleotide sequences of different HCV isolates of a same subtype may possibly possess the characteristics for different geographical distribution and so a definite epidemic HCV strain may emerge from a definite area.
authors.affiliation: Affiliated Hospital of Xuzhou Medical College, Xuzhou, 221002.
authors.forename: L
authors.initials: L
authors.lastname: Wei
authors.forename: Y
authors.initials: Y
authors.lastname: Wang
authors.forename: H
authors.initials: H
authors.lastname: Chen
mesh_terms: D001483:Base Sequence; D003001:Cloning, Molecular; D014644:Genetic Variation; D005838:Genotype; D016174:Hepacivirus / Q000235:genetics*; D006801:Humans; D008969:Molecular Sequence Data; D009154:Mutation; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D017384:Sequence Deletion; D017361:Viral Nonstructural Proteins / Q000235:genetics* / Q000276:immunology; D012324:RNA-Dependent RNA Polymerase
chemical_list: D017361:Viral Nonstructural Proteins; C087036:NS-5 protein, hepatitis C virus; D012324:RNA-Dependent RNA Polymerase