1.14.13.25 copper the enzyme expresses the soluble enzyme form under copper limitation, and the membrane-bound particulate MMO at high copper-to-biomass ratio, mechanism of the copper switch involves a tetrameric 480 kDA sensor protein MmoS, encoded by gene mmoS, as part of a two-component signaling system, domain organization, MmoS contains a FAD cofactor, indirect regulation without binding of copper to MmoS, overview 672049 1.14.13.25 Cu2+ cells adapted to the respective medium, either lacking Cu (sMMO production) or containing 0.01 mM Cu (pMMO production) 701759 1.14.13.25 Cu2+ component C contains no copper 438939 1.14.13.25 Cu2+ copper genetically regulates the enzyme activity of the soluble and membrane-bound form 438928, 438929 1.14.13.25 Cu2+ copper-containing protein component contains one copper atom per molecule 438921 1.14.13.25 Cu2+ cytochrome component contains 0.3-0.8 atoms copper per molecule 438921 1.14.13.25 Cu2+ expression of the genes encoding sMMO and pMMO is regulated by copper ions, with sMMO expressed solely when copper is limiting 703761 1.14.13.25 Cu2+ metal-binding titrations of MMOD and copper 765765 1.14.13.25 Cu2+ the membrane-bound pMMO contains 4.8 Cu2+ ions per 100 kDa protomer the purified pMMO contains 1.4 Cu2+ ions per 100 kDa protomer, the enzyme contains a dinuclear copper center 685262 1.14.13.25 Cu2+ when allylthiourea is removed, sMMO activity is maintained for an additional 24 generations, albeit at a slightly lower level due to the presence of 0.0007 mM of Cu2+ in the feed medium 704758 1.14.13.25 Fe Fe(IV) diiron complexes 764980 1.14.13.25 Fe structural comparison of the di-iron center of MMOH (PDB ID 1MHY), MMOH-MMOB (PDB ID 4GAM), and MMOH-MMOD. Conformational changes in the MMOH four-helix bundle (helices B, C, E, and F) upon MMOB and MMOD binding. Six residues that coordinate to the two iron atoms are distributed on to the different helices 765765 1.14.13.25 Fe the enzyme uses a nonheme, oxygen-bridged dinuclear iron cluster in the active site 764976 1.14.13.25 Fe the presence of iron at the diiron active site is required for the catalytic activity of the sMMO 764425 1.14.13.25 Fe the sMMOH active site contains a dinuclear iron cluster, which serves to activate molecular oxygen for insertion into the C-H bond of methane 764181 1.14.13.25 Fe2+ contains a diiron center 726546 1.14.13.25 Fe2+ contains Fe2+ 685272 1.14.13.25 Fe2+ enzyme sMMO contains a non-heme diiron active site 745389 1.14.13.25 Fe2+ MOOH contains 3.7-4.1 Fe atoms per dimer, binding structure and geometric configuration, EXAFS and Fourier transformation analysis, detailed overview 673999 1.14.13.25 Fe2+ spin states in the polynuclear [Fe2O2] core cluster, a dinuclear oxygen-bridged iron(IV) model for the intermediate Q of the hydroxylase component of methane monooxygenase by means of spin-unrestricted Kohn–Sham density functional theory, calculated coupling constants in calculation of Heisenberg coupling constants with Noodleman’s Broken-Symmetry approach, computational method, optimized cluster structures, overview 675083 1.14.13.25 Fe2+ the enzyme contains a Fe2S2 cluster, a bis-my-hydroxo-bridged dinuclear iron cluster, that binds to the enzyme reductase domain MMOR 675455 1.14.13.25 Fe2+ the Fe2S2 domain of the reductase protein transfers electrons to carboxylate-bridged di-iron centers in the hydroxylase component of sMMO, structure of the Fe2S2 (ferredoxin) domain of sMMO reductase, overview. The Fe2S2 cluster is a di-iron pair coordinated by the sulfur atoms of cysteine residues 42, 47, 50, and 82 746420 1.14.13.25 Fe2+ the purified pMMO contains 7.6 Fe2+ ions per 100 kDa protomer, the membrane-bound pMMO contains 2.1 Fe2+ ions per 100 kDa protomer 685262 1.14.13.25 Fe2+ the [2Fe-2S] cofactor of MMOR is a one-electron carrier, the ferredoxin center must transfer two electrons sequentially to MMOH to reduce fully each diiron(III) hydroxylase active site, overview 674158 1.14.13.25 Fe3+ the enzyme has diiron (FeIII-FeIII) active sites where different types of hydrocarbons are oxidized through orchestrated hydroxylase, regulatory and reductase components for precise control of hydrocarbons, oxygen, protons, and electrons 745535 1.14.13.25 Iron - 438932 1.14.13.25 Iron 1 mol Fe per mol enzyme 438925 1.14.13.25 Iron 1 mol of [2Fe-2S(S-Cys)4]centre per mol protein 438938 1.14.13.25 Iron 1.3-1.5 atoms iron per molecule 438939 1.14.13.25 Iron 2 g-atom iron 438938 1.14.13.25 Iron 2 mol Fe per mol enzyme 438924 1.14.13.25 Iron 2.1 mol Fe per mol enzyme 438925 1.14.13.25 Iron 2.3 mol Fe per mol protein 438931 1.14.13.25 Iron 2.8 mol Fe per mol protein 438926 1.14.13.25 Iron 3.6 mol of iron per mol of hydroxylase component A 438947 1.14.13.25 Iron 4.3 mol Fe per mol enzyme 438924 1.14.13.25 Iron a [2Fe-2S]cluster 438941 1.14.13.25 Iron active site diiron cluster 672102 1.14.13.25 Iron characterization of [Fe2-S2] redox centre of component C 438928, 438938 1.14.13.25 Iron component B of sMMO 438950 1.14.13.25 Iron contains an Fe4+(micro-O)2Fe4+ center. A terminal hydroxo and a protonated His147 which is dissociated from a nearby Fe, is more asymmetric in its Fe(micro-O)2Fe diamond core, and is another very good candidate for intermediate Q 704019 1.14.13.25 Iron contains hydroxo-bridged binuclear iron clusters 438941 1.14.13.25 Iron contains oxo-bridged binuclear iron clusters 438935, 438941 1.14.13.25 Iron cytochrome component contains 1 atom iron per molecule 438921 1.14.13.25 Iron in MmoH Fe-water distances vary from about 1.9 to 2.7 A, showing Fe1 to be 5 or 6 coordinate. The effect of binding toluene-4-monooxygenase D/MmoB to toluene-4-monooxygenase H/MmoH is not to remove a water ligand from either iron but to induce a change in orientation of the terminal glutamate on Fe2. This allows O2 to bridge the diiron site and aligns the redox active orbital on each Fe for efficient 2-electron transfer, facilitating the formation of a stabilized peroxo intermediate 704171 1.14.13.25 Iron non-heme diiron active site in the alpha-subunit. The regulatory component (MMOB) of soluble methane monooxygenase (sMMO) has a unique N-terminal tail not found in regulatory proteins of other bacterial multicomponent monooxygenases. This N-terminal tail is indispensable for proper function, yet its solution structure and role in catalysis remain elusive. The oxidation state of the hydroxylase component, MMOH, modulates the conformation of the N-terminal tail in the MMOH-2MMOB complex, which in turn facilitates catalysis. The N-terminal tail switches from a relaxed, flexible conformational state to an ordered state upon MMOH reduction from the diiron(III) to the diiron(II) state 745157 1.14.13.25 Iron non-heme iron, 3.02 mol iron per mol of enzyme, addition of exogenous FeCl2 or FeCl3 does not affect the enzyme activity 672690 1.14.13.25 Iron protein A, hydroxylase component: contains a binuclear iron center 438923 1.14.13.25 Iron protein C, reductase component: contains 1 [Fe2-S2] 438923, 438932 1.14.13.25 Iron soluble methane monooxygenase consists of three subunits: a hydroxylase bridged with binuclear iron cluster, an NADH-dependent reductase component containing both flavin adenine dinucleotide (FAD) and ferredoxin [Fe2S2] cofactors, and regulatory protein which controls the reaction between the previous two. Low-temperature activation of methane is primarily achieved via Fe/Fe complex in the hydroxylase subunit. The Fe2S2 complex in soluble methane monooxygenase reductase only acts as a wired mediator to assist electron transport from the NAD/FAD redox couple to the di-iron complex in the hydroxylase. NAD and FAD simultaneously bind to a canyon region located midway between the two lobes in the reductase, forming a continuous wire, assisting the electron transport. The regulatory protein plays a vital role in helping the hydroxylase and reductase subunits to interface and causing conformational changes that control methane oxidation 746420 1.14.13.25 Iron the diiron active site of each homodimer is located in the alpha subunit, and no other metal centers are present. The resting state active site (MMOHox) consists of two Fe(III) ions coordinated by Glu114, His147, and a solvent molecule (Fe1), and Glu209, Glu243, and His246 (Fe2). The iron ions are 3.1 A apart, coordinated in pseudooctahedral fashion and bridged by two solvent molecules as well as Glu144 745389 1.14.13.25 additional information does not require Cu2+ 671477 1.14.13.25 additional information sMMO activity and expression does not require Cu2+ 701759 1.14.13.25 additional information sMMO contains no metal ions 438950 1.14.13.25 additional information the enzyme contains very low or no amounts of copper and zinc 672690 1.14.13.25 additional information the enzyme does not contain and require Cu2+ for activity 745389 1.14.13.25 additional information the soluble methane monooxygenase contains no copper 745730 1.14.13.25 NaCl as a true halotolerant enzyme, MmoC still shows 50% of its specific activity at 2 M NaCl. Evaluation of salt tolerance for NADH-mediated reduction of benzyl viologen by MmoC at non-optima conditions, 23°C and pH 7.0 764485 1.14.13.25 Ni2+ protein B contains 0.04 mol Ni2+ per mol protein 438930 1.14.13.25 Zn2+ 0.2-0.5 mol zinc per mol protein 438931 1.14.13.25 Zn2+ component A, hydroxylase component: contains 0.5 mol zinc per mol protein 438926 1.14.13.25 Zn2+ the purified pMMO contains 1.3 Zn2+ ions per 100 kDa protomer, the membrane-bound pMMO contains 2.7 Zn2+ ions per 100 kDa protomer 685262 1.14.13.25 [2Fe-2S] cluster bound to the MMOR enzyme component 672130