Fig. 3: Structure of Mmp10 in complex with its peptide substrate.
From: Crystallographic snapshots of a B12-dependent radical SAM methyltransferase
a, Overview of Mmp10 in complex with peptide substrate, shown in orange (PDB code 7QBS). b, Close-up of the Mmp10 active site showing SAM in green, peptide substrate in orange and cobalamin in magenta. The distance between the C5′ atom of SAM and the Cδ atom of the arginine peptide substrate R285 (3.7 Å) and that between R285 and the methyl group of MeCbl (4.1 Å) are indicated by dashed lines. The omit map (blue mesh) of peptide is contoured at 3σ. c, Sequences of the peptides used as potential substrates with the substitution of arginine (R285) with isoleucine (Ile), leucine (Leu), ornithine (Orn), lysine (Lys), citrulline (Cit) or homoarginine (HArg). d, UV–visible light analysis of Mmp10 pre-incubated with OHCbl. Green line, OHCbl–Mmp10; blue line, OHCbl–Mmp10 after incubation with Ti(III) citrate; red line, reduced OHCbl–Mmp10 exposed to air. See Extended Data Figs. 4–6 for additional information.
