This view shows enzymes only for those organisms listed below, in the list of taxa known to possess the pathway. If an enzyme name is shown in bold, there is experimental evidence for this enzymatic activity.
Synonyms: vitamin B12 biosynthesis
|Superclasses:||Biosynthesis → Cofactors, Prosthetic Groups, Electron Carriers Biosynthesis → Vitamins Biosynthesis → Cobalamin Biosynthesis → Adenosylcobalamin Biosynthesis|
Expected Taxonomic Range: Proteobacteria
De novo synthesis of cobamides requires a great deal of genetic information, which is only found in some prokaryotes. Many bacterial species do not have the full genetic information required for de novo biosynthesis of coenzyme B12, but can synthesize cobalamin when supplied with cobinamide, a stable cobamide that is not a true intermediate of the de novo pathway [Ford55, Lawrence96].
In order to process cobinamide to coenzyme B12, it has to be converted into a real intermediate of the pathway. In most bacteria this is done by the attachment of the upper ligand 5'-deoxyadenosine to yield adenosylcobinamide, followed by phosphorylation to yield adenosyl-cobinamide phosphate, an intermediate of the de novo biosynthetic pathway (this pathway).
Archaebacteria as well as many bacterial species utilze a different salvage pathway, where adenosylcobinamide is first converted to adenosylcobyrate (see adenosylcobalamin salvage from cobinamide II).
Variants: adenosylcobalamin biosynthesis I (early cobalt insertion) , adenosylcobalamin biosynthesis II (late cobalt incorporation) , adenosylcobalamin salvage from cobalamin , adenosylcobalamin salvage from cobinamide II
Unification Links: EcoCyc:COBALSYN-PWY
Blanche91: Blanche F, Debussche L, Famechon A, Thibaut D, Cameron B, Crouzet J (1991). "A bifunctional protein from Pseudomonas denitrificans carries cobinamide kinase and cobinamide phosphate guanylyltransferase activities." J Bacteriol 1991;173(19);6052-7. PMID: 1655696
Buan06: Buan NR, Rehfeld K, Escalante-Semerena JC (2006). "Studies of the CobA-type ATP:Co(I)rrinoid adenosyltransferase enzyme of Methanosarcina mazei strain Go1." J Bacteriol 188(10);3543-50. PMID: 16672609
Cameron91: Cameron B, Blanche F, Rouyez MC, Bisch D, Famechon A, Couder M, Cauchois L, Thibaut D, Debussche L, Crouzet J (1991). "Genetic analysis, nucleotide sequence, and products of two Pseudomonas denitrificans cob genes encoding nicotinate-nucleotide: dimethylbenzimidazole phosphoribosyltransferase and cobalamin (5'-phosphate) synthase." J Bacteriol 1991;173(19);6066-73. PMID: 1917841
Chen95: Chen P, Ailion M, Weyand N, Roth J (1995). "The end of the cob operon: evidence that the last gene (cobT) catalyzes synthesis of the lower ligand of vitamin B12, dimethylbenzimidazole." J Bacteriol 177(6);1461-9. PMID: 7883701
Cheong01: Cheong CG, Escalante-Semerena JC, Rayment I (2001). "Structural investigation of the biosynthesis of alternative lower ligands for cobamides by nicotinate mononucleotide: 5,6-dimethylbenzimidazole phosphoribosyltransferase from Salmonella enterica." J Biol Chem 276(40);37612-20. PMID: 11441022
Cheong99: Cheong CG, Escalante-Semerena JC, Rayment I (1999). "The three-dimensional structures of nicotinate mononucleotide:5,6- dimethylbenzimidazole phosphoribosyltransferase (CobT) from Salmonella typhimurium complexed with 5,6-dimethybenzimidazole and its reaction products determined to 1.9 A resolution." Biochemistry 38(49);16125-35. PMID: 10587435
Debussche91: Debussche L, Couder M, Thibaut D, Cameron B, Crouzet J, Blanche F (1991). "Purification and partial characterization of Cob(I)alamin adenosyltransferase from Pseudomonas denitrificans." J Bacteriol 1991;173(19);6300-2. PMID: 1917862
DiazMejia09: Diaz-Mejia JJ, Babu M, Emili A (2009). "Computational and experimental approaches to chart the Escherichia coli cell-envelope-associated proteome and interactome." FEMS Microbiol Rev 33(1);66-97. PMID: 19054114
EscalanteSemere90: Escalante-Semerena JC, Suh SJ, Roth JR (1990). "cobA function is required for both de novo cobalamin biosynthesis and assimilation of exogenous corrinoids in Salmonella typhimurium." J Bacteriol 172(1);273-80. PMID: 2403541
Hsu05: Hsu FC, Ho TJ, Lai CC, Lin CF, Chen HP (2005). "Cloning, sequencing, expression, and single-step purification of the adenosylcobinamide kinase/adenosylcobinamide-phosphate guanylyltransferase (CobU) from Salmonella typhimurium ATCC 19585." Protein Expr Purif 42(1);178-81. PMID: 15939305
MaggioHall04: Maggio-Hall LA, Claas KR, Escalante-Semerena JC (2004). "The last step in coenzyme B(12) synthesis is localized to the cell membrane in bacteria and archaea." Microbiology 150(Pt 5);1385-95. PMID: 15133100
MaggioHall99: Maggio-Hall LA, Escalante-Semerena JC (1999). "In vitro synthesis of the nucleotide loop of cobalamin by Salmonella typhimurium enzymes." Proc Natl Acad Sci U S A 96(21);11798-803. PMID: 10518530
Neidhardt96: Neidhardt FC, Curtiss III R, Ingraham JL, Lin ECC, Low Jr KB, Magasanik B, Reznikoff WS, Riley M, Schaechter M, Umbarger HE "Escherichia coli and Salmonella, Cellular and Molecular Biology, Second Edition." American Society for Microbiology, Washington, D.C., 1996.
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