Figure 1.

Cleavage of oligonucleotides containing ɛC residues by E. coli cells extract. 5′-end or 3′-end ³²P-labeled oligonucleotides containing ɛC residues were incubated with E. coli AB1157 cell extract. The products of the reaction were separated on a 20% denaturing PAGE. Lane 1, 5′-end ³²P-labeled ɛC/G duplex oligonucleotide. Lane 2, as lane 1, but incubated with 5 μg of E. coli crude extracts for 10 min. Lane 3, 3′-end ³²P-labeled ɛC/G duplex oligonucleotide. Lane 4, same as lane 3, but incubated with 5 μg of crude extracts for 10 min. The products of the reaction were analyzed by electrophoresis on a denaturing 20% polyacrylamide gel and visualized by using the PhosphorImager (model Storm 840). For details see Materials and Methods.