Substitution at rt269 in Hepatitis B Virus Polymerase Is a Compensatory Mutation Associated with Multi-Drug Resistance
Fig 5
Molecular modeling of rtL269I of HBV polymerase.
(A) The three dimensional structure of the modeled HBV polymerase-DNA-TTP complex and (B) the expanded structure around rtL269. N-3 denotes the third nucleotide in the primer strand, starting from the 3′-end, just above the substrate-binding site. The domains of fingers, palm and thumb are shown in green, gray and pink colors, respectively. Also, the primer and template strand are shown in yellow and blue, respectively. TTP and active site residues (Asp83, Asp205 and Asp206) are colored by atom-types. The active site is noted as a dotted box. (C) When Leucine is mutated to isoleucine, residue 269 experiences steric clash with the neighboring rtR289 (block arrow), which would result in a conformational change in the primer binding residue, rtW284, and consequently, in the primer nucleotide, N-3 (dotted arrow).