Figure 4.

(A) Residues in NicA2 (light blue) adjacent to the FAD that are potentially redox active and could facilitate electron transfer between NicA2’s FAD and CycN’s heme in the NicA2-CycN complex predicted by AlphaFold2 Multimer. (B) Stopped-flow absorbance traces for the reaction of reduced NicA2 variants with CycN. Traces have been manually offset to facilitate comparison. Note the logarithmic time base. The solid line for each trace is the fit to a two-exponential function, and the k_obs values from these fits can be found in Table S3.