Adenosylcobalamin (AdoCbl)-dependent glutamate mutase fromClostrid-ium tetanomorphum comprises two weakly-associating subunits, MutS and MutE, which combine with AdoCbl to form the active holo-enzyme. Three coenzyme analogs, methylcobinamide (MeCbi), adenosylcobinamide (Ado-Cbi) and adeosylcobinamide-GDP (AdoCbi-GDP), were synthesized at milligram scale.