Biochemical Properties of Ectoine Hydroxylases from Extremophiles and Their Wider Taxonomic Distribution among Microorganisms
Figure 5
Crystal structure of the apo-form of the ectoine hydroxylase from V. salexigens.
(A) Overlay of the crystal structure of the apo-EctD protein (colored in grey) with the Fe-bound crystal structure of EctD (colored in orange) in cartoon representation. The Fe ion of the Fe-bound EctD protein is represented as a green sphere. Data coordinates for the iron-bound form of the V. salexigens EctD protein were taken from the protein database (PDB) entry 3EMR and those from the iron-free form were from PDB entry 4NMI. (B) Details of the molecular determinants of the iron-binding site of the V. salexigens EctD protein in its iron bound (orange) and iron-free (grey) forms. The side chains of the iron-binding residues Asp148, His146 and His248 are highlighted. Green and blue spheres represent the bound iron and water molecules, respectively.