Point mutations in conserved amino acid residues within the C-terminal domain of HIV-1 reverse transcriptase specifically repress RNase H function.

Two single site substitutions (E478----Q and H539----F) were introduced into the C-terminal RNase H domain of HIV-1 reverse transcriptase. These mutant proteins were expressed in Escherichia coli and purified by Ni2+-nitrilotriacetic acid affinity chromatography. Both enzymes are clearly defective in RNase H function, but exhibit wild type reverse transcriptase activity.