Most radical SAM enzymes use a [4Fe-4S] cluster to generate a 5′-deoxyadenosyl radical. Here the authors show the radical SAM thiamin pyrimidine synthase ThiC comprises an additional active site metal, probably representing an evolutionary link between the radical SAM and adenosylcobalamin-dependent enzyme superfamilies.
- Michael K. Fenwick
- Angad P. Mehta
- Steven E. Ealick