Structure-activity relationships in HIV-1 reverse transcriptase revealed by radiation target analysis

Protein Sci. 2003 Sep;12(9):2081-6. doi: 10.1110/ps.03130503.


Radiation target analysis is a powerful technique that can be used to determine both the structural and functional sizes of macromolecules. We have used this technique to probe the structure-function relationships of the recombinant forms of HIV-1 reverse transcriptase (RT). For the p66/p51 and p66/p66 dimeric forms of HIV-1 RT, both the structural and functional target sizes corresponded to that of the dimeric protein, indicating that a primary ionization in one subunit of the HIV-1 RT enzyme results in the concomitant polymer scission of both subunits. In contrast to p66/p51 and p66/p66 RT, the individually isolated p51 subunit of HIV-1 RT inactivated as a monomer. However, in the presence of a DNA template/primer substrate, the radiation inactivation analyses of p51 yielded a structural target size corresponding to that of a dimeric protein. This would indicate that the DNA substrate acted as a scaffold or template for p51 RT homodimer formation. In light of this observation, radiation inactivation studies can readily be applied to other DNA polymerase enzymes, such as the murine leukemia virus RT, for which the functional form of the enzyme has yet to be determined.

Publication types

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

MeSH terms

  • Chromatography, High Pressure Liquid
  • DNA-Directed DNA Polymerase / chemistry
  • Dimerization
  • Dose-Response Relationship, Radiation
  • Electrophoresis, Polyacrylamide Gel
  • HIV Reverse Transcriptase / chemistry*
  • Recombinant Proteins / chemistry
  • Structure-Activity Relationship


  • Recombinant Proteins
  • HIV Reverse Transcriptase
  • DNA-Directed DNA Polymerase