Zur Cobyrinsäure-Biosynthese. Gewinnung von Zwischenprodukten der Cobyrinsäure-Biosynthese mit Zellsuspensionen von<i>Propionibacterium shermanii</i>

Bergmann, Karl-Heinz; Deeg, Rolf; Gneuss, K.D.; Kriemler, Hans-Peter; Müller, Gerhard

doi:10.1515/bchm2.1977.358.2.1315

Cited by 39 publications

(19 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…UV and visible spectrum of a sample of factor II dilactone hexamethyl ester after extraction and purification from AR8639 cells grown in the absence of exogenous cobalt. The spectrum is identical to that reported by others (7,33). No such intermediate was extracted when the cells were grown in the presence of cobalt.…”

Section: Discussionsupporting

confidence: 88%

“…When AR8830 was grown in the presence of cobalt, no such intermediates could be detected but high levels of cobyric acid were obtained (Table 3; also see above). The accumulation of factors II and III in the absence of cobalt is thus similar to what has been observed with Propionibacterium shermanii (7,8,33).…”

Section: Analysis Of the 29 Isolated S Typhimurium Cob Mutants The supporting

confidence: 83%

“…The oxidized intermediates were identified on the basis of their UV and visible spectra, with maxima at A 376 and A 407 and mass spectra as follows: factor III dilactone, M ϩ 1 ϭ 957; factor II dilactone, M ϩ 1 ϭ 945) (Fig. 8 and data not shown) (7,33). When AR8830 was grown in the presence of cobalt, no such intermediates could be detected but high levels of cobyric acid were obtained (Table 3; also see above).…”

Section: Analysis Of the 29 Isolated S Typhimurium Cob Mutants The mentioning

confidence: 99%

See 2 more Smart Citations

Salmonella typhimurium cobalamin (vitamin B12) biosynthetic genes: functional studies in S. typhimurium and Escherichia coli

et al. 1996

View full text Add to dashboard Cite

In order to study the Salmonella typhimurium cobalamin biosynthetic pathway, the S. typhimurium cob operon was isolated and cloned into Escherichia coli. This approach has given the new host of the cob operon the ability to make cobalamins de novo, an ability that had probably been lost by this organism. In total, 20 genes of the S. typhimurium cob operon have been transferred into E. coli, and the resulting recombinant strains have been shown to produce up to 100 times more corrin than the parent S. typhimurium strain. These measurements have been performed with a quantitative cobalamin microbiological assay which is detailed in this work. As with S. typhimurium, cobalamin synthesis is only observed in the E. coli cobalamin-producing strains when they are grown under anaerobic conditions. Derivatives of the cobalamin-producing E. coli strains were constructed in which genes of the cob operon were inactivated. These strains, together with S. typhimurium cob mutants, have permitted the determination of the genes necessary for cobalamin production and classification of cbiD and cbiG as cobI genes. When grown in the absence of endogenous cobalt, the oxidized forms of precorrin-2 and precorrin-3, factor II and factor III, respectively, were found to accumulate in the cytosol of the corrinproducing E. coli. Together with the finding that S. typhimurium cbiL mutants are not complemented with the homologous Pseudomonas denitrificans gene, these results lend further credence to the theory that cobalt is required at an early stage in the biosynthesis of cobalamins in S. typhimurium.

show abstract

Section: Discussionsupporting

confidence: 88%

Section: Analysis Of the 29 Isolated S Typhimurium Cob Mutants The supporting

confidence: 83%

Section: Analysis Of the 29 Isolated S Typhimurium Cob Mutants The mentioning

confidence: 99%

See 1 more Smart Citation

Salmonella typhimurium cobalamin (vitamin B12) biosynthetic genes: functional studies in S. typhimurium and Escherichia coli

et al. 1996

View full text Add to dashboard Cite

show abstract

“…Very careful and delicate experiments with strict oxygen exclusion allowed Battersby and co-workers to determine the structure of the true intermediate as 15,23-dihydrosirohydrochlorin (compound 3) (6). The third step along the cobalamin pathway is a C-20 methylation (10,16,51). The trimethylated system, until now purified only as the ester of the oxidized form (factor III) (compound 8), is very likely to be biosynthesized and further transformed in the dihydro state (compound 4) (2), and the entire sequence from urogen III to cobyrinic acid probably occurs without any change of original oxidation level (4,60).…”

mentioning

confidence: 99%

“…Hepta-, hexa-, and pentacarboxyporphyrin III and factor III were isolated as methyl esters from cultures of strain SC510 (51), and factors I and II were isolated from cultures of strain SC510 Rifr (pXL190) (16,51). Cobester dicyanide was obtained by methanolysis of vitamin B12 (7).…”

mentioning

confidence: 99%

Purification and characterization of S-adenosyl-L-methionine: uroporphyrinogen III methyltransferase from Pseudomonas denitrificans

et al. 1989

View full text Add to dashboard Cite

S-Adenosyl-L-methionine:uroporphyrinogen III methyltransferase (SUMT), the enzyme of the cobalamin biosynthetic pathway which catalyzes C methylation of uroporphyrinogen III, was purified about 150-fold to homogeneity from extracts of a recombinant strain of Pseudomonas denitrificans derived from a cobalamin-overproducing strain by ammonium sulfate fractionation, anion-exchange chromatography, and hydroxyapatite chromatography. The purified protein has an isoelectric point of 6.4 and molecular weights of 56,500 as estimated by gel filtration and 30,000 as estimated by gel electrophoresis under denaturing conditions, suggesting that the active enzyme is a homodimer. It does not contain a chromophoric prosthetic group and does not seem to require metal ions or cofactors for activity. SUMT catalyzes the two successive C-2 and C-7 methylation reactions involved in the conversion of uroporphyrinogen III to precorrin-2 via the intermediate formation of precorrin-1. In vitro studies suggest that the intermediate monomethylated product (precorrin-1) is released from the protein and then added back to the enzyme for the second C-methylation reaction. The pH optimum was 7.7, the Km values for S-adenosyl-L-methionine and uroporphyrinogen III were 6.3 and 1.0 microM, respectively, and the turnover number was 38 h-1. The enzyme activity was shown to be completely insensitive to feedback inhibition by cobalamin and corrinoid intermediates tested at physiological concentration. At uroporphyrinogen III concentrations above 2 microM, SUMT exhibited a substrate inhibition phenomenon. It is suggested that this property might play a regulatory role in cobalamin biosynthesis in the cobalamin-overproducing strain studied.

show abstract

The Total Synthesis of Pyrrole Pigments 1973–1980

Jackson

1984

Total Synthesis of Natural Products

View full text Add to dashboard Cite

Zur Cobyrinsäure-Biosynthese. Gewinnung von Zwischenprodukten der Cobyrinsäure-Biosynthese mit Zellsuspensionen vonPropionibacterium shermanii

Cited by 39 publications

References 0 publications

Salmonella typhimurium cobalamin (vitamin B12) biosynthetic genes: functional studies in S. typhimurium and Escherichia coli

Salmonella typhimurium cobalamin (vitamin B12) biosynthetic genes: functional studies in S. typhimurium and Escherichia coli

Purification and characterization of S-adenosyl-L-methionine: uroporphyrinogen III methyltransferase from Pseudomonas denitrificans

The Total Synthesis of Pyrrole Pigments 1973–1980

Contact Info

Product

Resources

About