Figure 5. The interrelation of UvrABC^Tma and UvrABC^Bca in UvrABC incision reaction.

UvrABC incision reaction were performed in UvrABC buffer with subunit UvrA (10 nM), UvrB (250 nM) and UvrC (100 nM) in the presence of ³²P-labeled cis-BPDE DNA substrates. Substrates were preincubated with Bca UvrAB at 60 °C for 30 min, then Bca UvrC or Tma UvrC were individually added in reaction 1 and 2; or Tma UvrC and Bca UvrC were concurrently added in reaction5, with incubation 60 min at 60 °C. After preincubation of UvrAB with substrates, at reaction 3, Tma UvrC was added and incubated for 60 min then Bca UvrC was added sequentially for additional 60 min incubation; At reaction 4, Bca UvrC was added and incubated for 60 min then Tma UvrC was added sequentially for additional 60 min incubation at 60 °C. Reaction products were denatured and resolved by electrophoresis in 15% polyacrylamide gels containing 7.5 M urea.