Fig. 2

Heme region (A) and Mn2+-binding sites of Ape-MnP1 (B) and Cst-MnP1 (C). (A) Heme pocket of Ape-MnP1 (green) and Cst-MnP1 (blue), including His171/His170, Asp233/Asp232 and Phe188/Phe187 at the proximal side (below the heme plane); and His46/His47, Arg42/Arg43 and Phe45/Phe46 at the distal side (above the heme plane). Mn2+ binding in Ape-MnP1 (B) and Cst-MnP1 (C) confirmed by anomalous difference electron density maps contoured at 5σ, with the cation shown as a pink sphere