HPLC, UV-visible, and HRMS analysis of MftA M1W (A), MftA M1W/Y30F (B), MftA M1W/Y30S (C), and MftA M1W/Y30W (D). Each variant has a corresponding HPLC chromatogram (middle column), a UV-visible spectrum (middle column, inset), and an ion chromatogram (right column). HPLC analyses were carried out on a C4 HPLC column. For all HPLC and HRMS chromatograms, black is the unreacted MftA variant, and red represents the reaction with the MftA variant. For the UV-visible spectra, black is the unreacted MftA variant, red is the reacted MftA variant, and cyan is dAdo adduct to the Y30W variant. mAu, milliabsorbance units.