1.1.1.86 Co2+ the reaction requires a divalent metal ion 655530 1.1.1.86 Mg2+ - 686070, 763188 1.1.1.86 Mg2+ active site contains two divalent Mg2+ cations 762913 1.1.1.86 Mg2+ dependent on 738067, 738219 1.1.1.86 Mg2+ Km for Mg2+: 0.0045 mM, at pH 8.2, 30°C 639179 1.1.1.86 Mg2+ Km: 0.35 mM, pH 10, reaction with acetolactate 639178 1.1.1.86 Mg2+ Km: 0.4 mM, pH 8.5 639178 1.1.1.86 Mg2+ Km: 0.42 mM 639175 1.1.1.86 Mg2+ Km: 0.45 mM, pH 6.7, reaction with acetolactate 639178 1.1.1.86 Mg2+ Km: 0.5 mM 639184 1.1.1.86 Mg2+ Km: 0.77 mM 639174 1.1.1.86 Mg2+ Mg2+-dependent enzyme 762924 1.1.1.86 Mg2+ optimum concentration 5 mM 639171 1.1.1.86 Mg2+ required 33969, 639169, 639171, 639172, 639174, 639175, 639176, 639177, 639178, 639179, 639180, 639181, 639182, 639183, 639184, 639185, 639186, 639187, 670482, 731279 1.1.1.86 Mg2+ required for the alkyl migration reaction step 699243 1.1.1.86 Mg2+ required for the alkyl migration reaction, Km is 0.0072 mM, binding structure, overview 699584 1.1.1.86 Mg2+ required, KM: 0.00324 mM 670612 1.1.1.86 Mg2+ the coordination geometry for Mg(1) is approximately octahedral, with three water ligands and three protein ligands, the carboxylate groups of D217, E389 and E393. Mg(2) is seven coordinate with six waters and a carboxylate oxygen from D217. A dissociation constant of about 500 microM applies to the interaction of Mg2+ with unliganded enzyme. In presence of NADPH the Kd increases to about 800 microM 725718 1.1.1.86 Mg2+ the enzyme binds two Mg2+ ions in the active site to bridge the substrate ligand and protein. The substrate binding and catalytic efficiency of KARI are highly dependent on the Mg2+ concentration 763730 1.1.1.86 Mg2+ the enzyme utilizes Mg2+ in the enzyme catalysis 763172 1.1.1.86 Mg2+ the reaction requires a divalent metal ion 655530 1.1.1.86 Mg2+ two ions bind to enzyme 639182, 639187 1.1.1.86 Mg2+ two magnesium ions are located deep in the active site pocket and are separated by 4.7 A. The side chains of D188 and E192, and four water molecules form ligands with one of the Mg2+ ions, Mg2+(I), and the second Mg2+ ion, Mg2+ (II), is liganded also by the side-chain of D188, in addition to E224 and E228 and three water molecules 762999 1.1.1.86 Mg2+ with acetolactate as substrate , Mg2+ is the only divalent metal ion that supports enzyme catalysis 639175 1.1.1.86 Mn2+ activates reaction with 3-hydroxy-3-methyl-2-oxobutanoate, no effect on reaction with acetolactate 639175 1.1.1.86 Mn2+ the reaction requires a divalent metal ion 655530 1.1.1.86 additional information metal ions other than Mg2+ are inhibitory 639171 1.1.1.86 additional information Mn2+, Co2+, Ni2+, Zn2+, Ca2+, Cu2+ and Co3+ can not substitute for Mg2+ 639175, 639187 1.1.1.86 additional information no metal ions required 639170, 639187 1.1.1.86 additional information the enzyme catalyzes a two-step reaction: an alkyl migration that requires Mg2+, and a reduction reaction involving NADPH. For the reduction reaction, a divalent metal ion is also required, with any of Mg2+, Mn2+, Co2+, or Ni2+ utilized in this role 699584 1.1.1.86 additional information the NADPH reaction step requires a divalent cation, e.g. Mg2+, Mn2+, or Co2+, but in a non-specific manner 699243