ISSN:
1432-1432
Schlagwort(e):
Key words: Hepatitis C virus — Synonymous substitutions — Functional constraints — Transition bias — Codon preference — RNA secondary structure — Evolutionary rate — Virus origins
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Biologie
Notizen:
Abstract. Comparison of complete genome sequences for different variants of hepatitis C virus (HCV) reveals several different constraints on sequence change. Synonymous changes are suppressed in coding regions at both 5′ and 3′ ends of the genome. No evidence was found for the existence of alternative reading frames or for a lower mutation frequency in these regions. Instead, suppression may be due to constraints imposed by RNA secondary structures identified within the core and NS5b genes. Nonsynonymous substitutions are less frequent than synonymous ones except in the hypervariable region of E2 and, to a lesser extent, in E1, NS2, and NS5b. Transitions are more frequent than transversions, particularly at the third position of codons where the bias is 16:1. In addition, nucleotide substitutions may not occur symmetrically since there is a bias toward G or C at the third position of codons, while T ↔ C transitions were twice as frequent as A ↔ G transitions. These different biases do not affect the phylogenetic analysis of HCV variants but need to be taken into account in interpreting sequence change in longitudinal studies.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1007/PL00006226
Permalink
