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Choline oxidase catalyzes the oxidation of choline to glycine betaine, a compatible solute that accumulates in pathogenic bacteria and plants so they can withstand osmotic and temperature stresses. The crystal structure of choline oxidase was determined and refined to a resolution of 1.86 A with data collected at 100 K using synchrotron X-ray radiation. The(More)
The FAD-dependent NAD(P)H oxidase from Lactobacillus sanfrancisensis (L.san-Nox2) catalyzes the oxidation of 2 equivalents of either NADH or NADPH and reduces 1 equivalent of O(2) to yield 2 equivalents of water. During steady-state turnover only 0.5% of the reducing equivalents are detected in solution as hydrogen peroxide, suggesting that it is not(More)
By improving the expression and purification of Escherichia coli methionine aminopeptidase (eMetAP) and using slightly different crystallization conditions, the resolution of the parent structure was extended from 2.4 to 1.9 A resolution. This has permitted visualization of the coordination geometry and solvent structure of the active-site dinuclear metal(More)
Protocatechuate 3,4-dioxygenase (3,4-PCD) utilizes a ferric ion to catalyze the aromatic ring cleavage of 3,4-dihydroxybenzoate (PCA) by incorporation of both atoms of dioxygen to yield beta-carboxy-cis, cis-muconate. The crystal structures of the anaerobic 3,4-PCD.PCA complex, aerobic complexes with two heterocyclic PCA analogs, 2-hydroxyisonicotinic acid(More)
Protocatechuate 3,4-dioxygenase catalyzes the aromatic ring cleavage of 3,4-dihydroxybenzoate by incorporating both atoms of molecular oxygen to yield beta-carboxy-cis,cis-muconate. The structure of this metalloenzyme from Pseudomonas aeruginosa (now reclassified as P. putida) has been refined to an R-factor of 0.172 to 2.15 A resolution. The structure is a(More)
Pseudomonas testosteroni protocatechuate 4,5-dioxygenase and Pseudomonas putida catechol 2,3-dioxygenase (metapyrocatechase) catalyze extradiol-type oxygenolytic cleavage of the aromatic ring of their substrates. The essential active site Fe2+ of each enzyme binds nitric oxide (NO) to produce an EPR active complex with an electronic spin of S = 3/2.(More)
Methionine aminopeptidase (MetAP) exists in two forms (type I and type II), both of which remove the N-terminal methionine from proteins. It previously has been shown that the type II enzyme is the molecular target of fumagillin and ovalicin, two epoxide-containing natural products that inhibit angiogenesis and suppress tumor growth. By using mass(More)
The nonheme iron oxidase isopenicillin N synthase catalyzes the formation of two new internal bonds in the tripeptide delta-(L-alpha-aminoadipoyl)-L-cysteinyl-D-valine (ACV) to form the beta-lactam and thiazolidine rings of isopenicillin N. Concomitantly, O2 is reduced to 2 H2O. The recombinant enzyme from Cephalosporium acremonium (Mr = 38,400), expressed(More)
Flavin C4a-OO(H) and C4a-OH adducts are critical intermediates proposed in many flavoenzyme reaction mechanisms, but they are rarely detected even by rapid transient kinetics methods. We observe a trapped flavin C4a-OH or C4a-OO(H) adduct by single-crystal spectroscopic methods and in the 1.86 A resolution X-ray crystal structure of choline oxidase. The(More)