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The activation of ubiquitin and related protein modifiers is catalysed by members of the E1 enzyme family that use ATP for the covalent self-attachment of the modifiers to a conserved cysteine. The Escherichia coli proteins MoeB and MoaD are involved in molybdenum cofactor (Moco) biosynthesis, an evolutionarily conserved pathway. The MoeB- and E1-catalysed(More)
BACKGROUND Molybdenum cofactor (Moco) biosynthesis is an evolutionarily conserved pathway present in archaea, eubacteria, and eukaryotes. In humans, genetic abnormalities in the biosynthetic pathway result in Moco deficiency, which is accompanied by severe neurological symptoms and death shortly after birth. The Escherichia coli MoeA and MogA proteins are(More)
The chlorate-resistant mutants of Escherichia coli are affected in the biosynthesis of the molybdenum cofactor and show pleiotropic loss of the activities of those enzymes which require the cofactor. The molybdenum cofactor in all molybdoenzymes other than nitrogenase is a complex of the metal with a unique pterin termed molybdopterin. The molybdenum(More)
The molybdenum cofactor isolated from sulfite oxidase (sulfite: ferricytochrome c oxidoreductase, EC and xanthine dehydrogenase (xanthine:NAD+ oxidoreductase, EC in the presence of iodine and KI (form A) has been shown to contain a pterin nucleus with an unidentified substituent in the 6 position [Johnson, J. L., Hainline, B. E. &(More)
Molybdenum cofactor activity was found in the soluble fraction of cell-free extracts of Escherichia coli grown aerobically in media supplemented with molybdate. Cofactor was detected by its ability to complement the nitrate reductase-deficient mutant of Neurospora crossa, nit-1, resulting in the vitro formation of nitrate reductase activity. Acid treatment(More)
Denaturation of DNA photolyase (deoxyribodipyrimidine photolyase, EC from Escherichia coli with guanidine hydrochloride or acidification to pH 2 released, in addition to FAD, a chromophore with the spectral and chromatographic properties of a reduced pterin. Treatment of the enzyme with iodine prior to acidification converted the chromophore to a(More)
The early steps in the biosynthesis of the molybdopterin portion of the molybdenum cofactor have been investigated through the use of radiolabeled precursors. Labeled guanosine was added to growing cultures of the molybdopterin-deficient Escherichia coli mutant, moeB, which accumulates large amounts of precursor Z, the final intermediate in molybdopterin(More)
Molybdenum cofactor (Moco) biosynthesis is an evolutionarily conserved pathway present in eubacteria, archaea and eukaryotes, including humans. Genetic deficiencies of enzymes involved in Moco biosynthesis in humans lead to a severe and usually fatal disease. Moco contains a tricyclic pyranopterin, termed molybdopterin (MPT), that bears the cis-dithiolene(More)