KEGG   PATHWAY: bmf00020
Entry
bmf00020                    Pathway                                
Name
Citrate cycle (TCA cycle) - Brucella abortus 2308
Description
The citrate cycle (TCA cycle, Krebs cycle) is an important aerobic pathway for the final steps of the oxidation of carbohydrates and fatty acids. The cycle starts with acetyl-CoA, the activated form of acetate, derived from glycolysis and pyruvate oxidation for carbohydrates and from beta oxidation of fatty acids. The two-carbon acetyl group in acetyl-CoA is transferred to the four-carbon compound of oxaloacetate to form the six-carbon compound of citrate. In a series of reactions two carbons in citrate are oxidized to CO2 and the reaction pathway supplies NADH for use in the oxidative phosphorylation and other metabolic processes. The pathway also supplies important precursor metabolites including 2-oxoglutarate. At the end of the cycle the remaining four-carbon part is transformed back to oxaloacetate. According to the genome sequence data, many organisms seem to lack genes for the full cycle [MD:M00009], but contain genes for specific segments [MD:M00010 M00011].
Class
Metabolism; Carbohydrate metabolism
Pathway map
bmf00020  Citrate cycle (TCA cycle)
bmf00020

Module
bmf_M00009  Citrate cycle (TCA cycle, Krebs cycle) [PATH:bmf00020]
bmf_M00010  Citrate cycle, first carbon oxidation, oxaloacetate => 2-oxoglutarate [PATH:bmf00020]
bmf_M00011  Citrate cycle, second carbon oxidation, 2-oxoglutarate => oxaloacetate [PATH:bmf00020]
bmf_M00307  Pyruvate oxidation, pyruvate => acetyl-CoA [PATH:bmf00020]
Other DBs
GO: 0006099
Organism
Brucella abortus 2308 [GN:bmf]
Gene
BAB1_1170  gltA; Citrate synthase [KO:K01647] [EC:2.3.3.1]
BAB1_0090  Aconitate hydratase, C-terminal:Aconitate hydratase, N-terminal:Aconitate hydratase 1 [KO:K01681] [EC:4.2.1.3]
BAB1_1221  Isocitrate/isopropylmalate dehydrogenase:Isocitrate dehydrogenase NADP-dependent, eukaryotic [KO:K00031] [EC:1.1.1.42]
BAB1_1923  sucA; Dehydrogenase, E1 component:Transketolase, central region [KO:K00164] [EC:1.2.4.2]
BAB1_1922  sucB; Biotin/lipoyl attachment:Antifreeze protein, type I:Catalytic domain of components of various dehydrogenase complexes:Ribosom... [KO:K00658] [EC:2.3.1.61]
BAB1_1149  Pyridine nucleotide-disulphide oxidoreductase, class-II:Mercuric reductase:Pyridine nucleotide-disulphide oxidoreductase, cla... [KO:K00382] [EC:1.8.1.4]
BAB1_1918  lpdA-2; Pyridine nucleotide-disulphide oxidoreductase, class-II:NAD binding site:Adrenodoxin reductase:Mercuric reductase:Pyridine nu... [KO:K00382] [EC:1.8.1.4]
BAB2_0712  lpdA-3; Pyridine nucleotide-disulphide oxidoreductase, class-II:NAD binding site:Pyridine nucleotide-disulphide oxidoreductase, class... [KO:K00382] [EC:1.8.1.4]
BAB1_1925  CoA Binding Domain:Succinyl-CoA ligase, alpha subunit:ATP-citrate lyase/succinyl-CoA ligase [KO:K01902] [EC:6.2.1.5]
BAB1_1926  sucC; ATP-dependent carboxylate-amine ligase-like, ATP-grasp:Succinyl-CoA synthetase, beta subunit:ATP-citrate lyase/succinyl-CoA l... [KO:K01903] [EC:6.2.1.5]
BAB1_1077  Acetyl-CoA hydrolase/transferase [KO:K18118] [EC:2.8.3.18]
BAB1_1901  FAD-dependent pyridine nucleotide-disulphide oxidoreductase:Fumarate reductase/succinate dehydrogenase, FAD-binding site:Fuma... [KO:K00239] [EC:1.3.5.1]
BAB1_1900  4Fe-4S ferredoxin, iron-sulfur binding domain:Succinate dehydrogenase/fumarate reductase iron-sulfur protein:2Fe-2S ferredoxin [KO:K00240] [EC:1.3.5.1]
BAB1_1903  sdhC; Succinate dehydrogenase, cytochrome b subunit [KO:K00241]
BAB1_1902  unnamed protein product [KO:K00242]
BAB1_0977  Fumarate lyase:Fe-S type hydro-lyases tartrate/fumarate alpha region:Fe-S type hydro-lyases tartrate/fumarate beta region [KO:K01676] [EC:4.2.1.2]
BAB2_0186  fumC; Fumarate lyase:Delta crystallin:Fumarate hydratase, class II [KO:K01679] [EC:4.2.1.2]
BAB1_1927  mdh; Lactate/malate dehydrogenase:L-lactate dehydrogenase:TrkA potassium uptake protein [KO:K00024] [EC:1.1.1.37]
BAB1_1791  pyc; Biotin/lipoyl attachment:HMG-CoA lyase-like:Biotin-requiring enzyme, attachment site:Conserved carboxylase region:Carbamoyl-p... [KO:K01958] [EC:6.4.1.1]
BAB1_1152  Dehydrogenase, E1 component:Mitochondrial substrate carrier [KO:K00161] [EC:1.2.4.1]
BAB1_1151  Biotin/lipoyl attachment:2-oxo acid dehydrogenase, acyltransferase component, lipoyl-binding:Transketolase, central region:Tr... [KO:K00162] [EC:1.2.4.1]
BAB1_1150  aceF; Biotin/lipoyl attachment:Antifreeze protein, type I:Catalytic domain of components of various dehydrogenase complexes:2-oxo a... [KO:K00627] [EC:2.3.1.12]
BAB2_0032  Biotin/lipoyl attachment:Catalytic domain of components of various dehydrogenase complexes:2-oxo acid dehydrogenase, acyltran... [KO:K00627] [EC:2.3.1.12]
Compound
C00022  Pyruvate
C00024  Acetyl-CoA
C00026  2-Oxoglutarate
C00036  Oxaloacetate
C00042  Succinate
C00068  Thiamin diphosphate
C00074  Phosphoenolpyruvate
C00091  Succinyl-CoA
C00122  Fumarate
C00149  (S)-Malate
C00158  Citrate
C00311  Isocitrate
C00417  cis-Aconitate
C05125  2-(alpha-Hydroxyethyl)thiamine diphosphate
C05379  Oxalosuccinate
C05381  3-Carboxy-1-hydroxypropyl-ThPP
C15972  Enzyme N6-(lipoyl)lysine
C15973  Enzyme N6-(dihydrolipoyl)lysine
C16254  [Dihydrolipoyllysine-residue succinyltransferase] S-succinyldihydrolipoyllysine
C16255  [Dihydrolipoyllysine-residue acetyltransferase] S-acetyldihydrolipoyllysine
Reference
  Authors
Nishizuka Y (ed).
  Title
[Metabolic Maps] (In Japanese)
  Journal
Tokyo Kagaku Dojin (1980)
Reference
  Authors
Nishizuka Y, Seyama Y, Ikai A, Ishimura Y, Kawaguchi A (eds).
  Title
[Cellular Functions and Metabolic Maps] (In Japanese)
  Journal
Tokyo Kagaku Dojin (1997)
Reference
  Authors
Michal G.
  Title
Biochemical Pathways
  Journal
Wiley (1999)
Related
pathway
bmf00010  Glycolysis / Gluconeogenesis
bmf00053  Ascorbate and aldarate metabolism
bmf00061  Fatty acid biosynthesis
bmf00071  Fatty acid degradation
bmf00190  Oxidative phosphorylation
bmf00220  Arginine biosynthesis
bmf00250  Alanine, aspartate and glutamate metabolism
bmf00280  Valine, leucine and isoleucine degradation
bmf00350  Tyrosine metabolism
bmf00470  D-Amino acid metabolism
bmf00630  Glyoxylate and dicarboxylate metabolism
KO pathway
ko00020   
LinkDB

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