Figure 2.

Cys-122 is required for substrate reduction. A, RPC-HPLC chromatograms of Cd-MsrB WT, C66S, C122S, and C127S mutants are shown, where Met peak formation is observed at a retention time 7.45 min. In the presence of MetSO and DTT, as a reducing agent, the C122S mutant does not convert MetSO to Met, whereas the WT and the other mutants (C66S and C127S) show Met production. B, the concentration of Met produced by the WT and Cys mutants are shown in a dot plot. WT and the C127S mutant show similar Met production, whereas the C66S mutant shows 10-fold excess Met production. The data are presented as a mean ± S.E. of at least two independent technical repeats and the graphs were generated using Prism8.