In:
Antimicrobial Agents and Chemotherapy, American Society for Microbiology, Vol. 58, No. 11 ( 2014-11), p. 6861-6869
Abstract:
Resistance to the 2′-F-2′- C -methylguanosine monophosphate nucleotide hepatitis C virus (HCV) inhibitors PSI-352938 and PSI-353661 was associated with a combination of amino acid changes (changes of S to G at position 15 [S15G], C223H, and V321I) within the genotype 2a nonstructural protein 5B (NS5B), an RNA-dependent RNA polymerase. To understand the role of these residues in viral replication, we examined the effects of single and multiple point mutations on replication fitness and inhibition by a series of nucleotide analog inhibitors. An acidic residue at position 15 reduced replicon fitness, consistent with its proximity to the RNA template. A change of the residue at position 223 to an acidic or large residue reduced replicon fitness, consistent with its proposed proximity to the incoming nucleoside triphosphate (NTP). A change of the residue at position 321 to a charged residue was not tolerated, consistent with its position within a hydrophobic cavity. This triple resistance mutation was specific to both genotype 2a virus and 2′-F-2′- C -methylguanosine inhibitors. A crystal structure of the NS5B S15G/C223H/V321I mutant of the JFH-1 isolate exhibited rearrangement to a conformation potentially consistent with short primer-template RNA binding, which could suggest a mechanism of resistance accomplished through a change in the NS5B conformation, which was better tolerated by genotype 2a virus than by viruses of other genotypes.
Type of Medium:
Online Resource
ISSN:
0066-4804
,
1098-6596
DOI:
10.1128/AAC.03847-14
Language:
English
Publisher:
American Society for Microbiology
Publication Date:
2014
detail.hit.zdb_id:
1496156-8
SSG:
12
SSG:
15,3