Scheme 1.
The proposed mechanism of SmTGR. Two types of charge-transfer complexes (FADH−–NADP+ CTC and thiolate–FAD CTC) are shown by dashed arrows. Residues numbered without a prime are from one subunit and residues numbered with a prime are from the other subunit. The proposed mechanism is based on data in this paper and previous studies (24, 34, 39, 40).