Fig. 6. Xer recombination at psi and psiDC in the presence of XerC[De]. (A) Recombination of p-psi.psi and p-psiDC.psiDC in the presence of XerD and either XerC[De] or XerC. (B) Time course of recombination on p-psiDC.psiDC with XerC[De] and XerD. Reactions contained 40% glycerol and were cleaved with XhoI. Bands are indicated as follows: HJ, HJ intermediates; S, substrate fragments; P, product fragments.