Extended Data Fig. 7: Fe loop and cation site in Mmp10.

a, Fe loop in Mmp10 (Mmp10 MTA_1 structure). Cobalamin colored magenta, residues from Fe loop colored purple and residue from cobalamin binding domain colored teal. b, Cation site in Mmp10 (Mmp10 MTA_1 structure). Na ion (purple sphere) modelled in cation site with an average distance of 2.4 Å in octahedral conformation (grey dotted lines) from coordinating sidechains and water. Distance between Na ion and 4Fe4S cluster is 11 Å (yellow dotted line). Omit map of Na ion contoured at 3 σ level. 4Fe4S cluster shown as orange and yellow spheres next to SAM molecule depicted in green. c, Activity of the D156A mutant (upper panel) compared to the WT enzyme (lower panel). Reactions were analyzed by LC-MS. Methylated peptide [M+H] ⁺= 1510.79 (circles), 5′-dA [M+H] ⁺= 252.11 (squares) and SAH [M+H] ⁺= 385.13 (triangles). Experiments were performed in duplicate.