Fig. 3: Structural features of MetCaCb.
From: Discovery of a Ni2+-dependent heterohexameric metformin hydrolase
a The heterohexameric MetCaCb complex structure shown in ribbon (MetCa) and surface (MetCb) diagrams. Metal ions in the active sites are shown as green spheres. b Structural comparison of MetCa and MetCb. The atomic structures of α1 (claret) and β1(cyan) subunits are overlayed. The differential loops of MetCa or MetCb are indicated by black arrows. c Superposition of the active site-regions of MetCa and MetCb. Dashed black lines indicate metal coordination. d The conserved metal coordinating residues in representative sequences of arginase family proteins. Detailed information on the selected sequences can be found in the Methods section. Pos.: residue positions in MetCa. e The active site pocket in MetCa is capped by the N-terminal loop structure of MetCb. The residues around the entrance of pocket are shown as sticks. f Schematic drawing of the active site with a metformin molecule (purple stick) docked into it. The metal ion coordinating residues are colored in gray.
