Figure 4.
SbcCD cleaves a covalently closed dumbbell substrate. (A) Internally labeled, covalently closed dumbbell substrate (ccDB98) was incubated without (lane a) or with (lane b) SbcCD in the presence of ATPγS, at 16°C for 30 min. ∗, the position of the 32P-label. Reaction products then were resolved on a denaturing polyacrylamide gel. The 49- and 98-nt fragments produced are indicated (49 and ncDB98). (B) Preparative 10% polyacrylamide gel showing the single product obtained after the ligation of ncDB98. The upper band is covalently closed dumbbell (ccDB98), the lower band is nicked-circular dumbbell (ncDB98), which failed to ligate.