FIG. 5.

Cross-linking of XylE and XylT analogues. XylE (3.6 μM) was allowed to react with XylT, DmpQ, PhhQ, or NahT (20 μM) in the presence of EDC as described in Materials and Methods. Samples were analyzed by SDS-PAGE on a 12% polyacrylamide gel (lanes 2, 4, 6, and 8). The samples analyzed in lanes 3, 5, 7, and 9 were from cross-linking reactions performed in the presence of 0.1 M NaCl. Lane 1 was loaded with a mixture of unreacted XylE and XylT. The arrow indicates the cross-linked 46-kDa product.