The Polymorphisms, Solvent Accessibility and Conservatism of Hepatitis C Virus Nonstructural 5B Protein

ABSTRACT The polymorphisms of protein or protein family, that is, the divergences of amino acid and nucleotide sequences have provided much useful information on the divergent evolution of proteins. In this paper, we analyzed the polymorphisms of enzyme NS5B of HCV for which sequence variation among most isolates have been characterized and protein structures of the catalytic domain form of this enzyme are also known. For this protein, we found that solvent accessibility of residues in the protein structure is a strong predictor of whether or not an amino acid will be polymorphic and the residue variability. Apart from polymorphism, we found conservatism at every level among site is universal for this protein. We also found that purifying selection at different levels was strong in the forming of the polymorphisms and conservatism of this protein.