Distinctive pattern of sequence polymorphism in the NS3 protein of hepatitis C virus type 1b reflects conflicting evolutionary pressures.

ABSTRACT: Analysis of complete polyprotein-encoding sequences of hepatitis C virus genotype 1b (HCV-1b) showed evidence not only of past purifying selection but also of abundant slightly deleterious non-synonymous variants subject to ongoing purifying selection. The NS3 protein (with protease and NTPase/helicase activity) revealed less evidence of purifying selection acting on the cytotoxic T cells (CTL) epitopes than did the other proteins, whereas outside the CTL epitopes NS3 was more conserved than the other proteins. Moreover, NS3 showed a high incidence of forward-and-backward or parallel non-synonymous changes in CTL epitopes, as measured by the consistency index across the phylogeny of HCV-1b genomes computed at non-singleton non-synonymous polymorphic sites. This result implies that certain

SUBMITTER: Irausquin SJ 

PROVIDER: S-EPMC2577380 | biostudies-literature | 2008 Aug

REPOSITORIES: biostudies-literature