Fig. 2: TsaM catalyzes monooxygenation reactions to form hydroxymethyl containing products.

a The extracted ion chromatograms reveal that monooxygenated products, 4-(hydroxymethyl)benzenesulfonate (3, m/z = 187.0071 or 189.0013) and 4-(hydroxylmethyl)benzoate (4, m/z = 151.0041 or 153.0444) are formed when TsaM is provided with ¹⁸O-labeled or unlabeled H₂O₂ and p-toluenesulfonate (1) or 4-methylbenzoate (2), respectively. b Similar to that observed with H₂O₂, TsaM forms the expected products when combined with either TsaB or VanB. Of note, more substantial amounts of 4-(hydroxymethyl)benzenesulfonate and 4-(hydroxylmethyl)benzoate are formed with each substrate when VanB, rather than TsaB, is included in the reactions. The data in panel b reflects results previously described by our laboratory⁴⁸. Additional details for this panel regarding the measured total turnover numbers with the two different reductase proteins can be found in Supplementary Fig. 6.