Escherichia coli K-12 substr. MG1655 Enzyme: cobinamide adenosyltransferase / cobalamin adenosyltransferase

Gene: btuR Accession Numbers: EG10130 (EcoCyc), b1270, ECK1264

Synonyms: cobA

Regulation Summary Diagram: ?

Regulation summary diagram for btuR

E. coli K-12, as well as natural isolates, can synthesize cobalamin only when supplied with the intermediate cobinamide [Lawrence96]. Sequence similarity and complementation of a cobA mutant in Salmonella typhimurium suggests that btuR encodes the cobinamide adenosyltransferase [EscalanteSemere90, Suh93]. Cobinamide adenosyltransferase catalyzes the synthesis of adenosylcobalamin from a cobalamin precursor transported into the cell [Lundrigan89].

A btuR mutation leads to loss of repression of expression by externally supplied vitamin B12 and was therefore initially thought to encode a transcriptional repressor of btuB [Lundrigan87]. However, it was later shown that a btuR mutation results in a decrease in the pool of intracellular adenosylcobalamin and is thus more likely involved in the conversion of vitamin B12 to adenosylcobalamin [Lundrigan89]. Insertion mutants within btuR lead to an inability to utilize cobinamide under aerobic growth conditions [Lawrence95].

BtuR: "B twelve uptake regulation"

Locations: cytosol

Map Position: [1,325,791 <- 1,326,381] (28.58 centisomes, 103°)
Length: 591 bp / 196 aa

Molecular Weight of Polypeptide: 21.999 kD (from nucleotide sequence), 22 kD (experimental) [Lundrigan89 ]

pI: 6.47

Unification Links: ASAP:ABE-0004261 , CGSC:18493 , EchoBASE:EB0128 , EcoGene:EG10130 , EcoliWiki:b1270 , ModBase:P0A9H5 , OU-Microarray:b1270 , PortEco:btuR , PR:PRO_000022239 , Pride:P0A9H5 , Protein Model Portal:P0A9H5 , RefSeq:NP_415786 , RegulonDB:EG10130 , SMR:P0A9H5 , String:511145.b1270 , Swiss-Model:P0A9H5 , UniProt:P0A9H5

Relationship Links: InterPro:IN-FAMILY:IPR003724 , InterPro:IN-FAMILY:IPR025826 , InterPro:IN-FAMILY:IPR027417 , Pfam:IN-FAMILY:PF02572 , Pfam:IN-FAMILY:PF12557

Gene-Reaction Schematic: ?

Gene-Reaction Schematic

GO Terms:

Biological Process: GO:0009236 - cobalamin biosynthetic process Inferred from experiment Inferred by computational analysis [UniProtGOA12, UniProtGOA11a, GOA01, Lawrence95, Lundrigan89]
GO:0019250 - aerobic cobalamin biosynthetic process Inferred from experiment [Lawrence95]
GO:0006779 - porphyrin-containing compound biosynthetic process Inferred by computational analysis [UniProtGOA11a]
Molecular Function: GO:0000166 - nucleotide binding Inferred by computational analysis [UniProtGOA11a]
GO:0005524 - ATP binding Inferred by computational analysis [UniProtGOA11a, GOA01]
GO:0008817 - cob(I)yrinic acid a,c-diamide adenosyltransferase activity Inferred by computational analysis [GOA01a, GOA01, Suh93]
GO:0016740 - transferase activity Inferred by computational analysis [UniProtGOA11a]
Cellular Component: GO:0005737 - cytoplasm Inferred by computational analysis [UniProtGOA11, UniProtGOA11a]
GO:0005829 - cytosol Inferred by computational analysis [DiazMejia09]

MultiFun Terms: metabolism biosynthesis of building blocks cofactors, small molecule carriers cobalamin

Essentiality data for btuR knockouts: ?

Growth Medium Growth? T (°C) O2 pH Osm/L Growth Observations
LB Lennox Yes 37 Aerobic 7   Yes [Baba06, Comment 1]
M9 medium with 1% glycerol Yes 37 Aerobic 7.2 0.35 Yes [Joyce06, Comment 2]
MOPS medium with 0.4% glucose Yes 37 Aerobic 7.2 0.22 Yes [Baba06, Comment 1]
Yes [Feist07, Comment 3]

Last-Curated ? 23-May-2012 by Keseler I , SRI International

Enzymatic reaction of: cobinamide adenosyltransferase

EC Number:

cobinamide + ATP <=> adenosylcobinamide + PPPi

The reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, is in accordance with the direction of enzyme catalysis.

The reaction is physiologically favored in the direction shown.

In Pathways: adenosylcobalamin salvage from cobinamide I

Enzymatic reaction of: cobalamin adenosyltransferase

Synonyms: cob(I)alamin adenosyltransferase, corrinoid adenosyltransferase, aquacob(I)alamin adenosyltransferase, ATP:cob(I)alamin Co-β-adenosyltransferase

EC Number:

ATP + cob(I)alamin <=> coenzyme B12 + PPPi

The reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, is in accordance with the direction of enzyme catalysis.

The reaction is physiologically favored in the direction shown.

In Pathways: adenosylcobalamin salvage from cobalamin

Sequence Features

Protein sequence of cobinamide adenosyltransferase / cobalamin adenosyltransferase with features indicated

Feature Class Location Citations Comment
Nucleotide-Phosphate-Binding-Region 36 -> 42
UniProt: ATP; Non-Experimental Qualifier: by similarity;

Gene Local Context (not to scale): ?

Gene local context diagram

Transcription Unit:

Transcription-unit diagram


10/20/97 Gene b1270 from Blattner lab Genbank (v. M52) entry merged into EcoCyc gene EG10130; confirmed by SwissProt match.


Baba06: Baba T, Ara T, Hasegawa M, Takai Y, Okumura Y, Baba M, Datsenko KA, Tomita M, Wanner BL, Mori H (2006). "Construction of Escherichia coli K-12 in-frame, single-gene knockout mutants: the Keio collection." Mol Syst Biol 2;2006.0008. PMID: 16738554

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

Feist07: Feist AM, Henry CS, Reed JL, Krummenacker M, Joyce AR, Karp PD, Broadbelt LJ, Hatzimanikatis V, Palsson BO (2007). "A genome-scale metabolic reconstruction for Escherichia coli K-12 MG1655 that accounts for 1260 ORFs and thermodynamic information." Mol Syst Biol 3;121. PMID: 17593909

GOA01: GOA, DDB, FB, MGI, ZFIN (2001). "Gene Ontology annotation through association of InterPro records with GO terms."

GOA01a: GOA, MGI (2001). "Gene Ontology annotation based on Enzyme Commission mapping." Genomics 74;121-128.

Joyce06: Joyce AR, Reed JL, White A, Edwards R, Osterman A, Baba T, Mori H, Lesely SA, Palsson BO, Agarwalla S (2006). "Experimental and computational assessment of conditionally essential genes in Escherichia coli." J Bacteriol 188(23);8259-71. PMID: 17012394

Lawrence95: Lawrence JG, Roth JR (1995). "The cobalamin (coenzyme B12) biosynthetic genes of Escherichia coli." J Bacteriol 1995;177(22);6371-80. PMID: 7592411

Lawrence96: Lawrence JG, Roth JR (1996). "Evolution of coenzyme B12 synthesis among enteric bacteria: evidence for loss and reacquisition of a multigene complex." Genetics 142(1);11-24. PMID: 8770581

Lundrigan87: Lundrigan MD, De Veaux LC, Mann BJ, Kadner RJ (1987). "Separate regulatory systems for the repression of metE and btuB by vitamin B12 in Escherichia coli." Mol Gen Genet 206(3);401-7. PMID: 3108627

Lundrigan89: Lundrigan MD, Kadner RJ (1989). "Altered cobalamin metabolism in Escherichia coli btuR mutants affects btuB gene regulation." J Bacteriol 1989;171(1);154-61. PMID: 2644187

Suh93: Suh SJ, Escalante-Semerena JC (1993). "Cloning, sequencing and overexpression of cobA which encodes ATP:corrinoid adenosyltransferase in Salmonella typhimurium." Gene 129(1);93-7. PMID: 7916712

UniProt10: UniProt Consortium (2010). "UniProt version 2010-07 released on 2010-06-15 00:00:00." Database.

UniProtGOA11: UniProt-GOA (2011). "Gene Ontology annotation based on the manual assignment of UniProtKB Subcellular Location terms in UniProtKB/Swiss-Prot entries."

UniProtGOA11a: UniProt-GOA (2011). "Gene Ontology annotation based on manual assignment of UniProtKB keywords in UniProtKB/Swiss-Prot entries."

UniProtGOA12: UniProt-GOA (2012). "Gene Ontology annotation based on UniPathway vocabulary mapping."

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Please cite the following article in publications resulting from the use of EcoCyc: Nucleic Acids Research 41:D605-12 2013
Page generated by SRI International Pathway Tools version 19.0 on Tue Oct 13, 2015, biocyc13.