A single drug-resistance mutation in HSV-1 UL52 primase points to a difference between two helicase–primase inhibitors in their mode of interaction with the antiviral target

Abstract

By measuring the relative inhibitory concentrations required to overcome particular mutations in the helicase and primase proteins, evidence was obtained that BAY 57-1293 interacts with both components of the helicase-primase complex to achieve maximum potency, whereas for BILS 22BS, this may not be the case. Furthermore, our observations suggest that BAY 57-1293 interacts simultaneously with UL5 and UL52. Overall, the results suggest that these two potent HPIs interact differently with the helicase-primase complex.

A mutation in helicase motif IV of herpes simplex virus type 1 UL5 that results in reduced growth in vitro and lower virulence in a murine infection model is related to the predicted helicase structure

“…There were no mutations in the region containing Gly352, Met355 and Lys356, where UL5 HPI resistance mutations have been described previously (reviewed by Biswas & Field, 2008). Furthermore, neither BAY-pF-r3 nor PDK Rec-1 contained the UL52 Ala899Thr mutation, which is also known to confer resistance to BAY 57-1293 (Biswas et al, 2008b).…”

“…DNA from virus-infected Vero cells was amplified and bidirectionally sequenced in the HSV-1 UL5 (full) or UL52 (partial) genes, using multiple pairs of overlapping HSV-1-specific primers (Biswas et al, 2007a(Biswas et al, , 2008b. Full details of the PCRs and sequencing primers can be obtained in the supplementary online data associated with our previous paper (Biswas et al, 2008b; http://jac.oxfordjournals.org/ cgi/content/full/dkn057/DC1).…”

“…Full details of the PCRs and sequencing primers can be obtained in the supplementary online data associated with our previous paper (Biswas et al, 2008b; http://jac.oxfordjournals.org/ cgi/content/full/dkn057/DC1). BAY-pF-r3 contained a single substitution (Asn342Lys) at the upstream boundary of the UL5 functional motif IV.…”

“…This program uses a genetic algorithm to explore the full range of ligand conformational flexibility with partial flexibility of the protein, and satisfies the fundamental requirement that the ligand must displace loosely bound water on binding. The docking experiment was driven for BAY 57-1293 to bind to an interacting area of UL5, previously predicted by Biswas et al (2008b). A total of eight complexes showing higher scores were considered for this study.…”

“…In a previous study, the relative inhibitory concentrations required to overcome particular drug resistance mutations in UL5 or UL52 (including double mutants) suggested that BAY 57-1293 interacts with both components of the helicase-primase (HP) complex to achieve maximum potency (Biswas et al, 2008b). It was also postulated that BAY 57-1293 interacts simultaneously with UL5 and UL52, possibly involving residues Gly352, Met355 and Lys356 of UL5 and Ala899 of UL52 (Biswas et al, 2008b).…”