Biosynthesis of porphyrins and related macrocycles. Part 42. Pulse labelling experiments concerning the timing of cobalt insertion during vitamin B12 biosynthesis

Balachandran, Sarala; Vishwakarma, Ram A.; Monaghan, Sandra M.; Prelle, Annette; Stamford, N. Patrick J.; Leeper, Finian J.; Battersby, Alan R.

doi:10.1039/p19940000487

Cited by 25 publications

(15 citation statements)

References 4 publications

(1 reference statement)

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“…However, it seems likely that cobK and cbiJ are in fact similar (see below). These comparative genome studies, together with observations made with Propionibacterium shermanii (5,34,35) and other species, suggest that there is more than one pathway for corrin biosynthesis (11,48). The differences relate to the timing of the cobalt insertion and the method of ring contraction.…”

mentioning

confidence: 78%

“…It is interesting that the CbiL protein does not make precorrin-3 from precorrin-2 with good yields in vitro (data not shown and reference 42). Thus, the S. typhimurium vitamin B 12 biosynthetic pathway, like the pathway in Propionibacterium shermanii requires cobalt to be inserted at an early stage (5,8,11,35,48,49).…”

Section: Discussionmentioning

confidence: 99%

“…The differences relate to the timing of the cobalt insertion and the method of ring contraction. Thus, in S. typhimurium the cobalt may be inserted at an early stage of the biosynthesis, before the synthesis of precorrin-3, as in Propionibacterium shermanii (5,34,35), rather than at a later stage, after the synthesis of hydrogenobyrinic acid a,c-diamide, as it has been shown in P. denitrificans (22).…”

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confidence: 82%

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

et al. 1996

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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.

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confidence: 78%

Section: Discussionmentioning

confidence: 99%

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confidence: 82%

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

et al. 1996

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“…The reaction mixture contained 200 mM Tris-HCl buffer (pH 8.0) at 37°C, 5 mM MgCl 2 , 420 M CoCl 2 , 800 M ATP, and 150 M (CN) 2 Cbi in a final volume of 50 ml. The reaction mixture was made anoxic by bubbling with oxygen-free N 2 gas for 1 h at 25°C.…”

Section: Methodsmentioning

confidence: 99%

Identification of an Alternative Nucleoside Triphosphate: 5′-Deoxyadenosylcobinamide Phosphate Nucleotidyltransferase inMethanobacterium thermoautotrophicumΔH

Thomas

Escalante‐Semerena

2000

J Bacteriol

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Computer analysis of the archaeal genome databases failed to identify orthologues of all of the bacterial cobamide biosynthetic enzymes. Of particular interest was the lack of an orthologue of the bifunctional nucleoside triphosphate (NTP):5-deoxyadenosylcobinamide kinase/GTP:adenosylcobinamide-phosphate guanylyltransferase enzyme (CobU in Salmonella enterica). This paper reports the identification of an archaeal gene encoding a new nucleotidyltransferase, which is proposed to be the nonorthologous replacement of the S. enterica cobU gene. The gene encoding this nucleotidyltransferase was identified using comparative genome analysis of the sequenced archaeal genomes. Orthologues of the gene encoding this activity are limited at present to members of the domain Archaea. The corresponding ORF open reading frame from Methanobacterium thermoautotrophicum ⌬H (MTH1152; referred to as cobY) was amplified and cloned, and the CobY protein was expressed and purified from Escherichia coli as a hexahistidine-tagged fusion protein. This enzyme had GTP:adenosylcobinamide-phosphate guanylyltransferase activity but did not have the NTP:AdoCbi kinase activity associated with the CobU enzyme of S. enterica. NTP:adenosylcobinamide kinase activity was not detected in M. thermoautotrophicum ⌬H cell extract, suggesting that this organism may not have this activity. The cobY gene complemented a cobU mutant of S. enterica grown under anaerobic conditions where growth of the cell depended on de novo adenosylcobalamin biosynthesis. cobY, however, failed to restore adenosylcobalamin biosynthesis in cobU mutants grown under aerobic conditions where de novo synthesis of this coenzyme was blocked, and growth of the cell depended on the assimilation of exogenous cobinamide. These data strongly support the proposal that the relevant cobinamide intermediates during de novo adenosylcobalamin biosynthesis are adenosylcobinamide-phosphate and adenosylcobinamide-GDP, not adenosylcobinamide. Therefore, NTP:adenosylcobinamide kinase activity is not required for de novo cobamide biosynthesis.

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“…Cobalt is one of those trace metals that is present in the human body as a metal cofactor in the form of biologically important molecules such as the B 12 coenzyme and vitamin B 12 [4][5][6][7]. Cobalt is also known for its potent influence on human pathophysiological conditions, resulting either from its absence in the body, leading to anaemic symptoms [8], or its excessive presence, leading to toxic effects that result in heart disease [9].…”

Section: Introductionmentioning

confidence: 99%

Synthesis, Spectroscopic and X-ray Structural Study ofcis-diazidobis- (ethylenediamine)Cobalt(III) Thiocyanate

Sharma

Bala

Quirós

et al. 2003

Journal of Coordination Chemistry

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Reaction of cis-diazidobis(ethylenediamine)cobalt(III)nitrate with ammonium thiocyanate in a 1 : 2 molar ratio in aqueous medium gave the title cobalt(III) compound, cis-[Co(en) 2 (N 3 ) 2 ]SCN, as reddish brown crystals in almost quantitative yield. The complex salt was characterized by elemental analysis, IR, electronic, 1 H and 13 C NMR spectroscopic studies. An X-ray structure determination revealed an ionic structure with the monoclinic space group P2 1 /c, having cell dimensions a ¼ 12.1950(6), b ¼ 9.0317(5), c ¼ 12.6017(7) Å ; ¼ 113.419 (1) , V ¼ 1273.63(12) Å 3 and Z ¼ 4. The structure was refined by a full-matrix least-square procedures to R 1 ¼ 0.0297 and wR 2 ¼ 0.0697.

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Biosynthesis of porphyrins and related macrocycles. Part 42. Pulse labelling experiments concerning the timing of cobalt insertion during vitamin B12 biosynthesis

Cited by 25 publications

References 4 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

Identification of an Alternative Nucleoside Triphosphate: 5′-Deoxyadenosylcobinamide Phosphate Nucleotidyltransferase inMethanobacterium thermoautotrophicumΔH

Synthesis, Spectroscopic and X-ray Structural Study ofcis-diazidobis- (ethylenediamine)Cobalt(III) Thiocyanate

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