2.7.8.43 Fe3+ required, the peptA (eptA promoter) is induced sevenfold in the presence of Fe3+ 723212 2.7.8.43 Mg2+ metal ions present in the active site are coordinated to Thr280 and to residues conserved among the family of transferases 734476 2.7.8.43 Mg2+ required, two Mg2+ ions per enzyme molecule, binding structure model 734476 2.7.8.43 additional information three bound metal ions (two Zn2+ and a Mg2+) are implicated in catalysis 734476 2.7.8.43 Zn2+ a single Zn2+ atom is bound to ICR active site 760257 2.7.8.43 Zn2+ a zinc ion is present at a conserved site in addition to three zincs more peripherally located in the active site 760783 2.7.8.43 Zn2+ extracellular zinc induces phosphoethanolamine addition to Pseudomonas aeruginosa lipid A via the ColRS two-component system 739106 2.7.8.43 Zn2+ metal ions present in the active site are coordinated to Thr280 and to residues conserved among the family of transferases, interaction of the Zn2+ with the active site, binding site structure, overview. The second Zn2+ ion is coordinated by the side chains of His383, His465, and one of the oxygen atoms of the phosphate group attached to Thr280. In LptA, two types of coordination around the Zn1 are observed depending on the state of Thr280. In the case of non-phosphorylated Thr280, the coordination about Zn1 is tetrahedral with the fourth ligand being the free phosphate group. In contrast, when Thr280 is phosphorylated, a penta-coordinated metal is observed with the hydroxyl oxygen atom of Thr280 and one of the phosphate oxygen atoms each interacting weakly with the metal 734476 2.7.8.43 Zn2+ required, one Zn2+ ion per enzyme molecule coordinated tetrahedrally by the side chains of Glu240, Asp452, and His453 and the hydroxyl oxygen atom of Thr280, very strong binding to the enzyme, binding structure model 734476 2.7.8.43 Zn2+ zinc-binding residues of the phosphoenzyme intermediate, overview. The cEptC active site contains a tetrahedrally coordinated zinc ion and a putative nucleophilic threonine, Thr266, covalently bound to a phosphoryl group to form phosphothreonine 739786