1.1.99.38 | in complex with AdoMet and substrate, to 1.56 A resolution. Structure displays a modification to the core AdoMet radical fold, instead of the canonical (beta/alpha)6 architecture, BtrN displays a (beta5/alpha4) motif. An auxiliary [4Fe-4S] cluster in BtrN, thought to bind substrate, is instead implicated in substrate-radical oxidation |