INTERACTION OF C-TERMINAL SEQUENCES OF HUMAN-IMMUNODEFICIENCY-VIRUS REVERSE-TRANSCRIPTASE WITH TEMPLATE PRIMER

We have raised a rabbit monospecific antibody (designated C2003) against a synthetic peptide (CTP66) derived from a conserved sequence in the C-terminal portion of the p66 component of human immunodeficiency virus type 1 (HIV-1) reverse transcriptase (RT) (DeVico, A. L., Copeland, T. D., Veronese, F. D., Oroszlan, S., Gallo, R. C., and Sarngadharan, M. G. (1989) AIDS Res. Hum. Retroviruses 5, 51-60). This antibody directly inhibits the polymerase activity of HIV-1 RT and of RTs from a variety of retroviruses. HIV-1 RT is protected from this inhibition by preincubation of the enzyme with template primer prior to treatment with the antibody. Such protection is abrogated when the pretreatment is conducted under conditions of high ionic strength. Kinetic studies showed that the antibody-mediated inhibition is competitive with respect to template primer concentration. These results indicate that C2003 antibody acts to interfere with the template binding function of the enzyme and further indicates that conserved residues recognized by the antibody may be directly involved in this function.