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The hydrolytic haloalkane dehalogenases are promising bioremediation and biocatalytic agents. Two general classes of dehalogenases have been reported from Xanthobacter and Rhodococcus. While these enzymes share 30% amino acid sequence identity, they have significantly different substrate specificities and halide-binding properties. We report the 1.5 A(More)
The substrate specificities and product inhibition patterns of haloalkane dehalogenases from Xanthobacter autotrophicus GJ10 (XaDHL) and Rhodococcus rhodochrous (RrDHL) have been compared using a pH-indicator dye assay. In contrast to XaDHL, RrDHL is efficient toward secondary alkyl halides. Using steady-state kinetics, we have shown that halides are(More)
The biosynthesis of the 3,4-dihydroxybenzoate moieties of the siderophore petrobactin, produced by B. anthracis str. Sterne, was probed by isotopic feeding experiments in iron-deficient media with a mixture of unlabeled and D-[(13)C6]glucose at a ratio of 5:1 (w/w). After isolation of the labeled siderophore, analysis of the isotopomers was conducted via(More)
Penicillium charlesii secretes a galactofuranosyl and phosphodiester-containing peptidophosphogalactomannan (pPGM). A linear mannan was prepared from pPGM by treatment with 48% aqueous HF which selectively cleaves galactofuranosyl and phosphodiesters; treatment with alkaline borohydride releases the mannan from the polypeptide. Mannan from P. charlesii(More)
Pyridine nucleotide metabolism has been studied in vivo in a prokaryotic (Escherichia coli) and a eukaryotic (Saccharomyces cerevisiae) system cultured in a medium containing carbon-13-labeled nicotinic acid, followed by NMR detection of the labeled organisms. Chemical exchange between oxidized and reduced nucleotides is found to be sufficiently slow on the(More)
An intracellular coenzyme has been observed by carbon-13 nuclear magnetic resonance spectroscopy. The pyridine nucleotides in Escherichia coli were specifically labeled with carbon-13 from the biosynthetic precursor, nicotinic acid. The intracellular redox status and metabolic transformations of the pyridine nucleotides were examined under a variety of(More)
Angiosperms can be selected for the ability to grow in the presence of normally toxic concentrations of certain trace metal ions. Addition of Cd and Cu to Cd-resistant Datura innoxia cell cultures results in the rapid synthesis and accumulation of sulfur-rich, metal-binding polypeptides. The structure of these compounds was determined using amino acid(More)
Peptidophosphogalactomannan from Penicillium charlesii contains ethanolamine, presumably linked via phosphodiester to galactomannan (Rick, P. D., Drewes, L. R., and Gander, J. E., (1974) J. Biol. Chem. 249, 2072-2078). These investigations have been extended using 13C and 31P NMR spectroscopy to show that peptidophosphogalactomannan also contains choline(More)
MOTIVATION Stable isotope labeling of small-molecule metabolites (e.g. (13)C-labeling of glucose) is a powerful tool for characterizing pathways and reaction fluxes in a metabolic network. Analysis of isotope labeling patterns requires knowledge of the fates of individual atoms and moieties in reactions, which can be difficult to collect in a useful form(More)
Feeding experiments with isotope-labeled precursors rule out hydroxypyruvate and TCA cycle intermediates as the metabolic source of methoxymalonyl-ACP, the substrate for incorporation of "glycolate" units into ansamitocin P-3, soraphen A, and other antibiotics. They point to 1,3-bisphosphoglycerate as the source of the methoxymalonyl moiety and show that(More)