Table 2.

PFA-resistant mutants of HIV-1 RT.

Location in RT structure	How isolated?	Mutations	AZT sensitivity	Excision activity in vitro
dNTP binding site	Site-directed mutagenesis or bacterial library mutagenesis	D113G/E, A114S/G, Y115N/H, Q151H [66,70] R72A [71]	Hypersensitivity shown for D113E & A114S [70]	Reduced for A114S [72]
	From patients treated with NRTIs	K65R [73–76]	Suppression of AZT resistance [37,77–80]	Reduced for K65R [37,78]
Palm domain between the fingers domain and the template strand	From PFA-treated patients	W88S, W88G, Q161L, H208Y [68]	Suppression of AZT resistance shown for W88G and Q161L [37] No effect for W88S [37]	Reduced for W88G and Q161L [37] Not reduced for W88S [37]
	Serial passage of HIV-1 in culture	Q161L/H208Y [68] E89K, L92I, S156A [67] W88G, S117T, F160Y, M164I [76]	Suppression of AZT resistance shown for W88G, E89K, Q161L/H208Y, S117T, and M164I [37,67–69]	Reduced for W88G, E89K, Q161L/H208Y, S117T, and M164I [37]
	Site-directed or random mutagenesis	K154E, Y183S, G190R [66,70,81] E89G/T/A/D/V[82,83] V90A [84]	AZT sensitivity not determined in infectivity assays	Not done