Biosynthesis of 2'-deoxycoformycin by Streptomyces antibioticus
The biosynthesis of 2'-deoxycoformycin by Streptomyces antibioticus has been investigated. Previous studies indicated that a purine nycleoside is the precursor for ten of the eleven carbons of deoxycoformycin. It was proposed that carbon-7 of the seven-membered, 1,3-diazepine-ring of deoxycoformycin is not derived from the purine ring but by an insertion of a one-carbon unit between N-1 and C-6 of the purine ring. Carbon-1 of D-ribose has now been identified as the precursor for carbon 7 (and 1') of deoxycoformycin. Although the tetrahydrofolate/one-carbon pool contributes one carbon units to carbons-2 and 8 of the purine ring, which become carbons-5 and 2 of deoxycoformycin, it is not involved in the formation of carbon-7. The retention of the tritium on carbon-2 of (2,8-/sup 3/H)-adenosine in deoxycoformycin indicates that guanosine is not the nucleoside precursor of deoxycoformycin. The failure to detect the incorporation of /sup 18/O from (6-/sup 18/O)-inosine in deoxycoformycin suggests that inosine is not the purine nucleoside precursor of deoxycoformycin. Therefore, it is proposed that adenosine and carbon-1 and d-ribose are the carbon-nitrogen precursors of deoxycoformycin. A mechanism for the insertion of carbon-1 of d-ribose into the pyrimidine portion of the purine ring has been proposed. Using cell-free extracts of S. antibioticus, 8-ketodeoxycoformycin and 8-ketocoformycin can be converted to deoxycoformycin and coformycin, respectively. The enzyme which reduces the 8-keto groups has been characterized and partially purified.
- Research Organization:
- Temple Univ., Philadelphia, PA (USA)
- OSTI ID:
- 6524698
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
59 BASIC BIOLOGICAL SCIENCES
ADENOSINE
ANTI-INFECTIVE AGENTS
ANTIBIOTICS
BACTERIA
BIOSYNTHESIS
CHROMATOGRAPHY
DRUGS
EVEN-EVEN NUCLEI
ISOTOPES
LABELLED COMPOUNDS
LIGHT NUCLEI
LIQUID COLUMN CHROMATOGRAPHY
MICROORGANISMS
NUCLEI
NUCLEOSIDES
NUCLEOTIDES
ORGANIC COMPOUNDS
OXYGEN 18
OXYGEN ISOTOPES
PURIFICATION
RIBOSIDES
SEPARATION PROCESSES
STABLE ISOTOPES
STREPTOMYCES
SYNTHESIS
TRITIUM COMPOUNDS