Biosynthesis of the modified peptide antibiotic nosiheptide in Streptomyces actuosus
The biosynthesis of the modified, sulfur-rich peptide antibiotic nosiheptide (1) was studied in feeding experiments with radioactive and /sup 13/C-labeled precursors in Streptomyces actuosus. Following extensive chemical-shift assignments, /sup 13/C-labeled samples of 1 were analyzed by /sup 13/C NMR spectroscopy. In addition to supporting the expected origin of the thiazole ring and the L-cysteine moiety from cysteine, the L-threonine and butyrine moieties from threonine, and the hydroxyglutamate moiety from glutamate, the results demonstrated that the dehydroalanine moiety arises by dehydration of serine. The pyridine ring is formed uniquely by tail-to-tail condensation of two serine residues. As demonstrated by a double-labeling experiment, the indolic acid moiety arises by a novel intramolecular rearrangement of tryptophan in which the carboxyl group is connected to C2 of the indole and the ..cap alpha..-carbon and the amino nitrogen are eliminated. Only the hydroxymethyl group at C4 of the indole ring is derived by a C-methylation, but not via 4-methyltryptophan. The results define the sequence of a hypothetical peptide precursor of 1. 34 references, 3 figures, 4 tables.
- Research Organization:
- Ohio State Univ., Columbus (USA)
- OSTI ID:
- 6181056
- Journal Information:
- J. Am. Chem. Soc.; (United States), Journal Name: J. Am. Chem. Soc.; (United States) Vol. 110:17; ISSN JACSA
- Country of Publication:
- United States
- Language:
- English
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ANTI-INFECTIVE AGENTS
ANTIBIOTICS
BACTERIA
BIOSYNTHESIS
CARBON 13
CARBON ISOTOPES
DATA
DRUGS
EVEN-ODD NUCLEI
EXPERIMENTAL DATA
INFORMATION
ISOTOPES
LABELLED COMPOUNDS
LIGHT NUCLEI
MICROORGANISMS
NMR SPECTRA
NUCLEI
NUMERICAL DATA
SPECTRA
STABLE ISOTOPES
STREPTOMYCES
SYNTHESIS