Nucleotide precursor in riboflavin biosynthesis.
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چکیده
منابع مشابه
Biosynthesis of Riboflavin.
The biosynthesis of riboflavin requires 1 equivalent of GTP and 2 equivalents of ribulose phosphate. The first committed reactions of the convergent pathway are catalyzed by GTP hydrolase II and 3,4-dihydroxy-2-butanone 4-phosphate synthase. The initial reaction steps afford 5-amino-6-ribitylaminopyrimidine 5'-phosphate, which needs to be dephosphorylated by a hitherto elusive hydrolase. The de...
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The 5,6-dimethylbenzimidazole formed from riboflavin in cobalt-containing cells of Propionibacterium shermanii can only be isolated as a component of vitamin Blz. No free 5,6-dimethylbenzimidazole is detectable in these bacteria. In order to determine, if nevertheless the vitamin Bn biosynthesis proceeds via free 5,6-dimethylbenzimidazole, cells of P. shermanii were incubated with [5-‘“Nlribofl...
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We studied the incorporation of 14C-labeled guanosine into riboflavin under conditions precluding the metabolic conversion of guanosine compounds to free guanine. For this purpose we isolated a mutant BM 2 of Salmonella typhimurium deficient in the enzymes IMP dehydrogenase, purine nucleoside phosphorylase, and purine nucleotide pyrophosphorylase. The mutant incorporated [ribose-14C]guanosine i...
متن کاملTransfer RNA biosynthesis: the nucleotide sequence of a precursor to serine and proline transfer RNAs.
The nucleotide sequence of a transfer RNA precursor molecule coded by bacteriophage T4 has been determined. The molecule is a single polynucleotide chain which contains two transfer RNA species that are destined to recognize serine and proline. The 3' -CCA(OH) termini of both mature transfer RNA species are absent in the precursor molecule; these termini must therefore be added enzymatically at...
متن کاملPrecursor directed biosynthesis of aureobasidins.
The antifungal antibiotic aureobasidin A (AbA) is a cyclic depsipeptide composed of eight amino acids and a hydroxy acid. New Ab analogs were produced by feeding various amino acids to Aureobasidium pullulans R 106 c-712 in a chemically-defined medium containing glucose and ammonium sulfate. The constituent amino acids of AbA at positions 3 (L-phenylalanine), 4 (N-methyl-L-phenylalanine), 5 (L-...
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ژورنال
عنوان ژورنال: Journal of Nutritional Science and Vitaminology
سال: 1976
ISSN: 0301-4800,1881-7742
DOI: 10.3177/jnsv.22.477