MetaCyc Enzyme: L-aspartate oxidase

Gene: nadB Accession Numbers: EG10631 (MetaCyc), b2574, ECK2572

Synonyms: nic, nicB

Species: Escherichia coli K-12 substr. MG1655

L-aspartate oxidase (NadB) is the first enzyme in the de novo NAD biosynthesis pathway, catalyzing the FAD-dependent oxidation of L-aspartate to iminoaspartate [Mortarino96]. NadB activity is required for NAD biosynthesis under both aerobic and anaerobic conditions [Messner02]; fumarate is the more efficient electron acceptor and is used under anaerobic conditions, while oxygen appears to be the predominant electron acceptor under aerobic conditions due to the lower fumarate levels [Korshunov10].

The enzyme can exist in monomeric and dimeric form depending on pH [Tedeschi99, Mattevi99]. Crystal structures of the apo- and holoenzyme have been determined, suggesting that an unusual tertiary structure is shared by L-aspartate oxidase, the SdhA subunit of succinate dehydrogenase, and the FrdA subunit of fumarate reductase [Mattevi99, Bossi02].

NadB is a predominant source of hydrogen peroxide under aerobic conditions [Korshunov10].

Amino acid residues important for enzymatic activity have been identified by site-directed mutagenesis [Mortarino96, Tedeschi01]. The E121 residue is essential and thought to be required for orienting the L-aspartate substrate in a productive binding mode; mutants lose L-aspartate oxidase activity, but retain fumarate reductase activity [Tedeschi10].

NadB: "NAD biosynthesis" [Tritz70]

Locations: cytosol

Map Position: [2,708,442 -> 2,710,064]

Molecular Weight of Polypeptide: 60.337 kD (from nucleotide sequence), 60.0 kD (experimental) [Flachmann88 ]

pI: 5.6 [Seifert90]

Unification Links: ASAP:ABE-0008471 , CGSC:466 , DIP:DIP-556N , EchoBASE:EB0625 , EcoGene:EG10631 , EcoliWiki:b2574 , ModBase:P10902 , OU-Microarray:b2574 , PortEco:nadB , PR:PRO_000023333 , Pride:P10902 , Protein Model Portal:P10902 , RefSeq:NP_417069 , RegulonDB:EG10631 , SMR:P10902 , String:511145.b2574 , UniProt:P10902

Relationship Links: InterPro:IN-FAMILY:IPR003953 , InterPro:IN-FAMILY:IPR005288 , InterPro:IN-FAMILY:IPR013027 , InterPro:IN-FAMILY:IPR015939 , InterPro:IN-FAMILY:IPR027477 , PDB:Structure:1CHU , PDB:Structure:1KNP , PDB:Structure:1KNR , Pfam:IN-FAMILY:PF00890 , Pfam:IN-FAMILY:PF02910 , Prints:IN-FAMILY:PR00368

Gene-Reaction Schematic: ?

Gene-Reaction Schematic

GO Terms:

Biological Process: GO:0034628 - 'de novo' NAD biosynthetic process from aspartate Inferred from experiment [Kerr73]
GO:0009435 - NAD biosynthetic process Inferred by computational analysis [UniProtGOA12, GOA01]
GO:0019363 - pyridine nucleotide biosynthetic process Inferred by computational analysis [UniProtGOA11]
GO:0055114 - oxidation-reduction process Inferred by computational analysis [UniProtGOA11, GOA01]
Molecular Function: GO:0008734 - L-aspartate oxidase activity Inferred from experiment Inferred by computational analysis [GOA01a, GOA01, Mortarino96, Flachmann88]
GO:0044318 - L-aspartate:fumarate oxidoreductase activity Inferred from experiment Inferred by computational analysis [GOA01a, Tedeschi96]
GO:0050660 - flavin adenine dinucleotide binding Inferred from experiment [Mortarino96]
GO:0016491 - oxidoreductase activity Inferred by computational analysis [UniProtGOA11, GOA01]
Cellular Component: GO:0005829 - cytosol Inferred from experiment Inferred by computational analysis [DiazMejia09, Ishihama08]
GO:0005737 - cytoplasm Inferred by computational analysis [UniProtGOA11a, UniProtGOA11, GOA01]

MultiFun Terms: metabolism biosynthesis of building blocks cofactors, small molecule carriers nicotinamide adenine dinucleotide

Imported from EcoCyc 02-Jun-2015 by Paley S , SRI International

Enzymatic reaction of: L-aspartate oxidase

EC Number: 1.5.99.-

L-aspartate + fumarate <=> 2-iminosuccinate + succinate + H+

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.

Alternative Substrates for fumarate: oxygen [Tedeschi96 ]

Imported from EcoCyc 02-Jun-2015 by Paley S , SRI International

Cofactors or Prosthetic Groups: FAD [Korshunov10]

Enzymatic reaction of: L-aspartate oxidase

Synonyms: quinolinate synthetase B, L-aspartate:oxygen oxidoreductase (deaminating), L-aspartate:oxygen transhydrogenase, LASPO

EC Number:

L-aspartate + oxygen <=> 2-iminosuccinate + hydrogen peroxide + H+

The reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, is in accordance with the direction in which it was curated.

The reaction is physiologically favored in the direction shown.

Alternative Substrates for oxygen: fumarate [Tedeschi96 ] , a quinone [Tedeschi97 ]

In Pathways: aspartate superpathway , NAD biosynthesis I (from aspartate)

Imported from EcoCyc 02-Jun-2015 by Paley S , SRI International

The midpoint potential of the FAD/FADH2 couple is -216 mV [Tedeschi97].

Cofactors or Prosthetic Groups: FAD [Comment 1, Seifert90, Wicks78, Mortarino96]

Inhibitors (Competitive): NAD+ [Griffith75, Nasu82, Tedeschi99, Comment 2] , meso-tartrate [Seifert90, Nasu82]

Inhibitors (Noncompetitive): cibacron blue 3GA [Nasu82]

Inhibitors (Unknown Mechanism): 2-iminosuccinate [Mortarino96]

Primary Physiological Regulators of Enzyme Activity: NAD+

Kinetic Parameters:

Km (μM)

pH(opt): 8.0 [Nasu82]

Sequence Features

Feature Class Location Citations Comment
Nucleotide-Phosphate-Binding-Region 12 -> 26
UniProt: FAD; Non-Experimental Qualifier: potential;
Sequence-Conflict 160
[Nashimoto95, Flachmann88, UniProt10]
UniProt: (in Ref. 1, 3 and 4);
Active-Site 244
UniProt: Non-Experimental Qualifier: by similarity;
Active-Site 263
UniProt: Non-Experimental Qualifier: by similarity;
Sequence-Conflict 485
[Flachmann88, UniProt10]
UniProt: (in Ref. 1; CAA31217);

10/20/97 Gene b2574 from Blattner lab Genbank (v. M52) entry merged into EcoCyc gene EG10631; confirmed by SwissProt match.


Bossi02: Bossi RT, Negri A, Tedeschi G, Mattevi A (2002). "Structure of FAD-bound L-aspartate oxidase: insight into substrate specificity and catalysis." Biochemistry 41(9);3018-24. PMID: 11863440

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

Flachmann88: Flachmann R, Kunz N, Seifert J, Gutlich M, Wientjes FJ, Laufer A, Gassen HG (1988). "Molecular biology of pyridine nucleotide biosynthesis in Escherichia coli. Cloning and characterization of quinolinate synthesis genes nadA and nadB." Eur J Biochem 1988;175(2);221-8. PMID: 2841129

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.

Griffith75: Griffith GR, Chandler JL, Gholson RK (1975). "Studies on the de novo biosynthesis of NAD in Escherichia coli. The separation of the nadB gene product from the nadA gene product and its purification." Eur J Biochem 54(1);239-45. PMID: 238844

Ishihama08: Ishihama Y, Schmidt T, Rappsilber J, Mann M, Hartl FU, Kerner MJ, Frishman D (2008). "Protein abundance profiling of the Escherichia coli cytosol." BMC Genomics 9;102. PMID: 18304323

Kerr73: Kerr TJ, Tritz GJ (1973). "Cross-feeding of Escherichia coli mutants defective in the biosynthesis of nicotinamide adenine dinucleotide." J Bacteriol 115(3);982-6. PMID: 4353874

Korshunov10: Korshunov S, Imlay JA (2010). "Two sources of endogenous hydrogen peroxide in Escherichia coli." Mol Microbiol 75(6);1389-401. PMID: 20149100

Mattevi99: Mattevi A, Tedeschi G, Bacchella L, Coda A, Negri A, Ronchi S (1999). "Structure of L-aspartate oxidase: implications for the succinate dehydrogenase/fumarate reductase oxidoreductase family." Structure Fold Des 7(7);745-56. PMID: 10425677

Messner02: Messner KR, Imlay JA (2002). "Mechanism of superoxide and hydrogen peroxide formation by fumarate reductase, succinate dehydrogenase, and aspartate oxidase." J Biol Chem 277(45);42563-71. PMID: 12200425

Mortarino96: Mortarino M, Negri A, Tedeschi G, Simonic T, Duga S, Gassen HG, Ronchi S (1996). "L-aspartate oxidase from Escherichia coli. I. Characterization of coenzyme binding and product inhibition." Eur J Biochem 239(2);418-26. PMID: 8706749

Nashimoto95: Nashimoto H., Saito N. (1995). Data submission to EMBL/GenBank/DDBJ databases on 1995-09.

Nasu82: Nasu S, Wicks FD, Gholson RK (1982). "L-Aspartate oxidase, a newly discovered enzyme of Escherichia coli, is the B protein of quinolinate synthetase." J Biol Chem 1982;257(2);626-32. PMID: 7033218

Seifert90: Seifert J, Kunz N, Flachmann R, Laufer A, Jany KD, Gassen HG (1990). "Expression of the E. coli nadB gene and characterization of the gene product L-aspartate oxidase." Biol Chem Hoppe Seyler 1990;371(3);239-48. PMID: 2187483

Tedeschi01: Tedeschi G, Ronchi S, Simonic T, Treu C, Mattevi A, Negri A (2001). "Probing the active site of L-aspartate oxidase by site-directed mutagenesis: role of basic residues in fumarate reduction." Biochemistry 40(15);4738-44. PMID: 11294641

Tedeschi10: Tedeschi G, Nonnis S, Strumbo B, Cruciani G, Carosati E, Negri A (2010). "On the catalytic role of the active site residue E121 of E. colil-aspartate oxidase." Biochimie. PMID: 20600565

Tedeschi96: Tedeschi G, Negri A, Mortarino M, Ceciliani F, Simonic T, Faotto L, Ronchi S (1996). "L-aspartate oxidase from Escherichia coli. II. Interaction with C4 dicarboxylic acids and identification of a novel L-aspartate: fumarate oxidoreductase activity." Eur J Biochem 239(2);427-33. PMID: 8706750

Tedeschi97: Tedeschi G, Zetta L, Negri A, Mortarino M, Ceciliani F, Ronchi S (1997). "Redox potentials and quinone reductase activity of L-aspartate oxidase from Escherichia coli." Biochemistry 36(51);16221-30. PMID: 9405056

Tedeschi99: Tedeschi G, Negri A, Ceciliani F, Mattevi A, Ronchi S (1999). "Structural characterization of l-aspartate oxidase and identification of an interdomain loop by limited proteolysis." Eur J Biochem 260(3);896-903. PMID: 10103021

Tritz70: Tritz GJ, Matney TS, Gholson RK (1970). "Mapping of the nadB locus adjacent to a previously undescribed purine locus in Escherichia coli K-12." J Bacteriol 102(2);377-81. PMID: 4315893

UniProt10: UniProt Consortium (2010). "UniProt version 2010-11 released on 2010-11-02 00:00:00." Database.

UniProt10a: 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 manual assignment of UniProtKB keywords in UniProtKB/Swiss-Prot entries."

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

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

Wicks78: Wicks FD, Sakakibara S, Gholson RK (1978). "Evidence for an intermediate in quinolinate biosynthesis in Escherichia coli." J Bacteriol 136(1);136-41. PMID: 361684

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Please cite the following article in publications resulting from the use of MetaCyc: Caspi et al, Nucleic Acids Research 42:D459-D471 2014
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