Insertion of a small peptide of six amino acids into the β7–β8 loop of the p51 subunit of HIV-1 reverse transcriptase perturbs the heterodimer and affects its activities

Table 1 Effect of duplication of the β7–β8 loop in either or both the subunits of HIV-1 RT on the polymerase activity of the enzyme

	Percent of wild type polymerase Activity
Enzyme Species	Poly (rA).(dT)₁₈	U-5 PBSRNA/17-mer	U-5 PBS DNA/17-mer
p66 ^WT /p51 ^WT	100	100	100
p66 ^WT /p66 ^WT	92.6	82.5	85.6
p66 ^INS /p66 ^INS	1.5	11	10
p66 ^INS /p51 ^INS	0.6	1.2	2
p66 ^INS /p51 ^WT	98	106	97
p66 ^INS /p51 ^D186A	103	116	96
p66 ^WT /p51 ^INS	60	57	65

The polymerase activities of the wild type HIV-1 RT and its mutant derivatives carrying insertion of 6 amino acids in the β7-β8 loop of either or both the subunits were determined with the indicated template primer at saturating dNTP concentrations. Reactions were carried out at 37°C for 3 min and the total picomoles of nucleotide incorporated were determined. The values are expressed as a percentage of the wild type polymerase activity and are an average of three independent experiments.

ISSN: 1471-2091