Site-directed mutagenesis of the conserved Asp-443 and Asp-498 carboxy-terminal residues of HIV-1 reverse transcriptase.

AUTOR(ES)

Mizrahi, V

RESUMO

Substitution of the conserved Asp-443 residue of HIV-1 reverse transcriptase by asparagine specifically suppressed the ribonuclease H activity of the enzyme without affecting the reverse transcriptase activity, suggesting involvement of this ionizable residue at the ribonuclease H active site. An analogous asparagine substitution of the Asp-498 residue yielded an unstable enzyme that was difficult to enzymatically characterize. However, the instability caused by the Asn-498 mutation was relieved by the introduction of a second distal Asn-443 substitution, yielding an enzyme with wild type reverse transcriptase activity, but lacking ribonuclease H activity.

Documentos Relacionados

• Site-directed mutagenesis of the catalytic residues Asp-52 and Glu-35 of chicken egg white lysozyme.
• N-Terminal Protease of Pestiviruses: Identification of Putative Catalytic Residues by Site-Directed Mutagenesis
• Yeast farnesyl-diphosphate synthase: site-directed mutagenesis of residues in highly conserved prenyltransferase domains I and II.
• Site-directed mutagenesis of histidine residues in Clostridium perfringens alpha-toxin.
• Site-directed mutagenesis of amino acid residues of protein phosphatase 1 involved in catalysis and inhibitor binding