Enzymatic synthesis and structure of precorrin-3, a trimethyldipyrrocorphin intermediate in Vitamin B sub 12 biosynthesis
- Texas A and M Univ., College Station (United States)
The trimethylated intermediate of vitamin B{sub 12} (corrin) biosynthesis, precorrin-3, was produced from various {sup 13}C-enriched isotopomers of 5-aminolevulinic acid (ALA), using a multiple-enzyme system containing ALA dehydratase, porphobilinogen deaminase, uro'gen III synthetase, and the S-adenosyl-L-methionine- (SAM)-dependent uro'gen III methyltransferase (M-1) and precorrin-2 methyltransferase (M-2) in the presence of ({sup 13}C)SAM. Structural analysis of the resulting product, precorrin-3, reveals a close similarity to precorrin-2 but with several subtle differences in the conjugated array of C{double bond}C and C{double bond}N bonds which reflect the presence of the new C-methyl group at C20 and its influence on the electronic distribution in the dipyrrocorphin chromophore. The implications of this structure for corrin biosynthesis are discussed.
- OSTI ID:
- 5488978
- Journal Information:
- Biochemistry; (United States), Vol. 31:2; ISSN 0006-2960
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
VITAMIN B-12
BIOSYNTHESIS
CARBON 13
METHYL TRANSFERASES
NMR SPECTRA
NUCLEAR MAGNETIC RESONANCE
REACTION INTERMEDIATES
ULTRAVIOLET SPECTRA
VISIBLE SPECTRA
CARBON ISOTOPES
CARBON-GROUP TRANSFERASES
DRUGS
ENZYMES
EVEN-ODD NUCLEI
HEMATINICS
HEMATOLOGIC AGENTS
ISOTOPES
LIGHT NUCLEI
MAGNETIC RESONANCE
NUCLEI
ORGANIC COMPOUNDS
PROTEINS
RESONANCE
SPECTRA
STABLE ISOTOPES
SYNTHESIS
TRANSFERASES
VITAMIN B GROUP
VITAMINS
550201* - Biochemistry- Tracer Techniques