SNAP output for PDB entry 8x21 [SNAP web server]

PDB-id

8x21; SNAP-derived features in text and JSON formats; DNAproDB

Class

transferase

Method

X-ray (2.33 Å)

Summary

Hiv-1 reverse transcriptase mutant q151m-y115f-f116y-l74v:DNA:etv-tp ternary complex

Reference

Yasutake Y, Hattori SI, Kumamoto H, Tamura N, Maeda K, Mitsuya H (2024): "Deviated binding of anti-HBV nucleoside analog E-CFCP-TP to the reverse transcriptase active site attenuates the effect of drug-resistant mutations." Sci Rep, 14, 15742. doi: 10.1038/s41598-024-66505-z.

Abstract

While certain human hepatitis B virus-targeting nucleoside analogs (NAs) serve as crucial anti-HBV drugs, HBV yet remains to be a major global health threat. E-CFCP is a 4'-modified and fluoromethylenated NA that exhibits potent antiviral activity against both wild-type and drug-resistant HBVs but less potent against human immunodeficiency virus type-1 (HIV-1). Here, we show that HIV-1 with HBV-associated amino acid substitutions introduced into the RT's dNTP-binding site (N-site) is highly susceptible to E-CFCP. We determined the X-ray structures of HBV-associated HIV-1 RT mutants complexed with DNA:E-CFCP-triphosphate (E-CFCP-TP). The structures revealed that exocyclic fluoromethylene pushes the Met184 sidechain backward, and the resultant enlarged hydrophobic pocket accommodates both the fluoromethylene and 4'-cyano moiety of E-CFCP. Structural comparison with the DNA:dGTP/entecavir-triphosphate complex also indicated that the cyclopentene moiety of the bound E-CFCP-TP is slightly skewed and deviated. This positioning partly corresponds to that of the bound dNTP observed in the HIV-1 RT mutant with drug-resistant mutations F160M/M184V, resulting in the attenuation of the structural effects of F160M/M184V substitutions. These results expand our knowledge of the interactions between NAs and the RT N-site and should help further design antiviral NAs against both HIV-1 and HBV.