Figure 4.

Gp₄ddA synthesis activity of HIV-1 RT, AMV RT, and M-MuLV RT. (A) Products formed after incubation of 5 nM [³²P]ddAMP-terminated L32 primer annealed to WL50 template, 3.2 mM GTP, and no enzyme for 1h at 37°C (lane1); the indicated amounts of HIV-1 RT for 3 min at 37°C (lanes 2–4); AMV RT (Boehringer Mannheim) for 1h at 42°C (lanes 5–7); or M-MuLV RT (GIBCO/BRL) for 1h at 37°C (lanes 8–10). (B) Products formed by the reaction described in A with 200 nM HIV-1 RT and the indicated concentrations of Cl-TIBO for 15 min at 37°C (lanes 1–8), or with 700 nM M-MuLV RT and the indicated concentrations of Cl-TIBO for 1 h at 37°C (lanes 9–16). The highest concentration of Cl-TIBO contained 20% dimethyl sulfoxide, the solvent for this compound. Lanes 1 and 9 (0*) show products formed in the absence of Cl-TIBO but in the presence of 20% dimethyl sulfoxide.