Balo A, Caruso A, Tao L, Tantillo D, Seyedsayamdost M, Britt D. Trapping a cross-linked lysine-tryptophan radical in the catalytic cycle of the radical SAM enzyme SuiB. Proc Natl Acad Sci U S A. 2021;118(21). PMCID: PMC8166192