Use of chimeric human immunodeficiency virus types 1 and 2 reverse transcriptases for structure-function analysis and for mapping susceptibility to nonnucleoside inhibitors

J Acquir Immune Defic Syndr Hum Retrovirol. 1996 Apr 1;11(4):326-33. doi: 10.1097/00042560-199604010-00002.


The human immunodeficiency virus type 1 and type 2 (HIV-1 and HIV-2) reverse transcriptases (RTs) are evolutionary related. To study the effect of homologous sequence replacements on polymerase function and to map the determinants of the lack of susceptibility of HIV-2 RT to nonnucleoside drugs, a series of chimeric HIV-1/HIV-2 RTs were constructed. Analysis of the chimeric RTs showed that wild-type levels of RNA-dependent DNA polymerase activity were retained when both finger and palm subdomains were exchanged as a unit between the two parental RTs. Analysis of enzymatically active chimeras for inhibition by the thiobenzimidazolone derivative TIBO R82150 showed that a segment of HIV-2 RT at 212-250, when placed in the HIV-1 RT context, conferred a 40-fold decrease in susceptibility to TIBO R82150. Site-directed mutagenesis of this segment found Tyr227 to be a key residue in this segment for the natural resistance of HIV-2 RT to TIBO R82150.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acids / physiology
  • Base Sequence
  • Benzodiazepines / pharmacology*
  • HIV Reverse Transcriptase
  • HIV-1 / enzymology*
  • HIV-2 / enzymology*
  • Humans
  • Imidazoles / pharmacology*
  • Molecular Sequence Data
  • Mutagenesis, Site-Directed
  • Protein Conformation
  • RNA-Directed DNA Polymerase / chemistry
  • RNA-Directed DNA Polymerase / genetics
  • RNA-Directed DNA Polymerase / metabolism*
  • Recombinant Fusion Proteins / chemistry
  • Recombinant Fusion Proteins / metabolism
  • Reverse Transcriptase Inhibitors / pharmacology*
  • Structure-Activity Relationship


  • Amino Acids
  • Imidazoles
  • Recombinant Fusion Proteins
  • Reverse Transcriptase Inhibitors
  • R 82150
  • Benzodiazepines
  • reverse transcriptase, Human immunodeficiency virus 2
  • HIV Reverse Transcriptase
  • RNA-Directed DNA Polymerase