Fig. 4.

High conservation of a catalytic core in cMCR-1, cEptA, and cEptC. a Residues around the Zn²⁺ ion in cMCR-1. The Zn²⁺ ion is penta-coordinated, as indicated by yellow dotted lines. Glu246, Asp465, and His466 as well as the hydroxyl oxygen atom of Thr285 and one of the phosphate oxygen atoms are involved in the coordination of Zn²⁺. b Residues around the Zn²⁺ ion in cEptA. The coordination of two Zn²⁺ ions is shown by the yellow dotted line. One oxygen atom in the phosphate group swings aside to coordinate another Zn²⁺ ion together with H383 and H465. c Superposition of cMCR-1 and cEptA. The oxygen atoms in the phosphate group are shown in different positions by rotating at a specific angle. d Residues around the Zn²⁺ ion in cEptC. The coordination of Zn²⁺ is shown by the yellow dotted line. One oxygen atom in the phosphate group swings aside but does not coordinate the Zn²⁺ ion, unlike in cMCR-1. e Superposition of cMCR-1 and cEptC. The oxygen atoms in the phosphate group are shown in different positions by rotating at a specific angle. Subsequently, the side chain of H358 in cEptC (labeled as H395 in cMCR-1 in the parentheses) swings aside