Table 4. Accuracy of WT and mutant RTs in M13mp2 lacZα forward mutation assays.

RT	Total plaques	Mutant plaques	Mutant frequencya
WT HIV-2	9660	120	0.01242
K65R HIV-2	4750	56	0.01179 (1.1)
K65R/Q151M/M184V HIV-2	5142	53	0.01031 (1.2)
BH10 HIV-1	2915	58	0.01990 (0.6)

^aBackground frequencies in these assays were estimated to be less than one in 20,000 plaques⁴⁰. Numbers between parentheses indicate the fold-increase in fidelity relative to the WT HIV-2 RT.