Reaction Scheme: 7-carboxy-7-deazaguanine synthase (Cx14CxxC type), Radical SAM superfamily Reaction 221
| Scheme name: | 7-carboxy-7-deazaguanine synthase (Cx14CxxC type), Radical SAM superfamily | ||||
|---|---|---|---|---|---|
| Reaction: | 7-carboxy-7-deazaguanine synthase | ||||
| Description: | Enzymatic activity requires a [4Fe-4S] complex that binds SAM through its "free" apical iron ion. The binding motif for this enzyme is the non-canonical Cx14Cx2C (rather than Cx3Cx2C). The mechanism proceeds via the 5'-Ado radical, that abstracts the hydrogen atom from the C6 of the ring. The substrate it coordinated and thus stabilized by a Mg(II) ion. The reactive intermediate then undergoes rearrangement and ring collapse to form the product. | ||||
| Curator notes: | Mechanism is available from PMID:24362703. | ||||
