Wilson A Francisco

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Quercetin 2,3-dioxygenase from Bacillus subtilis (QueD) converts the flavonol quercetin and molecular oxygen to 2-protocatechuoylphloroglucinolcarboxylic acid and carbon monoxide. QueD, the only known quercetin 2,3-dioxygenase from a prokaryotic organism, has been described as an Fe2+-dependent bicupin dioxygenase. Metal-substituted QueDs were generated by(More)
MS/MS techniques in proteomics make possible the identification of proteins from organisms with little or no genome sequence information available. Peptide sequences are obtained from tandem mass spectra by matching peptide mass and fragmentation information to protein sequence information from related organisms, including unannotated genome sequence data.(More)
The temperature dependence of the primary and secondary intrinsic isotope effects for the C-H bond cleavage catalyzed by peptidylglycine alpha-hydroxylating monooxygenase has been determined. Analysis of the magnitude and Arrhenius behavior of the intrinsic isotope effects provides strong evidence for the use of tunneling as a primary catalytic strategy for(More)
Few studies have been conducted to identify the extracellular proteins and enzymes secreted by filamentous fungi, particularly with respect to dispensable metabolic pathways. Proteomic analysis has proven to be the most powerful method for identification of proteins in complex mixtures and is suitable for the study of the alteration of protein expression(More)
The protein YxaG from Bacillus subtilis, of previously unknown function, was found to have quercetin 2,3-dioxygenase activity when overexpressed in Escherichia coli. The enzyme converts the flavonol quercetin to 2-protocatechuoylphloroglucinol carboxylic acid and carbon monoxide, indicating that it performs the same reaction and yields the same products as(More)
The multicopper oxidase phenoxazinone synthase (PHS) catalyzes the penultimate step in the biosynthesis of the antibiotic actinomycin D by Streptomyces antibioticus. PHS exists in two oligomeric forms: a dimeric form and a hexameric form, with older actinomycin-producing cultures containing predominately the hexameric form. The structure of hexameric PHS(More)
Bacterial luciferase catalyzes the formation of visible light, FMN, and a carboxylic acid from FMNH2, O2, and the corresponding aldehyde. The reactive cysteinyl residue at position 106 of the alpha subunit has been replaced by serine, alanine, and valine by site-directed mutagenesis (Baldwin, T. O., Chen L. H., Chlumsky, L. J., Devine, J. H., and Ziegler,(More)
Filamentous fungi have been recognized as extraordinary producers of secreted proteins and are known to produce novel proteins and enzymes through dispensable metabolic pathways. Here, methods are described for the isolation and enrichment of samples of secreted proteins from cultures of filamentous fungi for analysis by gel electrophoresis and mass(More)
Soluble methane monooxygenase (sMMO) contains a nonheme, carboxylate-bridged diiron site that activates dioxygen in the catalytic oxidation of hydrocarbon substrates. Oxygen kinetic isotope effects (KIEs) have been determined under steady-state conditions for the sMMO-catalyzed oxidation of CH(3)CN, a liquid substrate analog. Kinetic studies of the(More)
Peptidylglycine alpha-amidating enzyme (alpha-AE) and dopamine beta-monooxygenase (D beta M), two copper-dependent monooxygenases that have catalytic and structural similarities, are irreversibly inactivated by sodium sulfite in a time- and concentration-dependent manner. Studies with alpha-AE show that the sulfite-mediated inactivation is dependent on the(More)