KEGG   ENZYME: 4.2.1.114Help
Entry
EC 4.2.1.114                Enzyme                                 

Name
methanogen homoaconitase;
methanogen HACN
Class
Lyases;
Carbon-oxygen lyases;
Hydro-lyases
BRITE hierarchy
Sysname
(R)-2-hydroxybutane-1,2,4-tricarboxylate hydro-lyase [(1R,2S)-1-hydroxybutane-1,2,4-tricarboxylate-forming]
Reaction(IUBMB)
(R)-2-hydroxybutane-1,2,4-tricarboxylate = (1R,2S)-1-hydroxybutane-1,2,4-tricarboxylate (overall reaction) [RN:R09720];
(1a) (R)-2-hydroxybutane-1,2,4-tricarboxylate = (Z)-but-1-ene-1,2,4-tricarboxylate + H2O [RN:R03444];
(1b) (Z)-but-1-ene-1,2,4-tricarboxylate + H2O = (1R,2S)-1-hydroxybutane-1,2,4-tricarboxylate [RN:R04371]
Reaction(KEGG)
Substrate
(R)-2-hydroxybutane-1,2,4-tricarboxylate [CPD:C01251];
(Z)-but-1-ene-1,2,4-tricarboxylate [CPD:C04002];
H2O [CPD:C00001]
Product
(1R,2S)-1-hydroxybutane-1,2,4-tricarboxylate [CPD:C05662];
(Z)-but-1-ene-1,2,4-tricarboxylate [CPD:C04002];
H2O [CPD:C00001]
Comment
This enzyme catalyses several reactions in the pathway of coenzyme-B biosynthesis in methanogenic archaea. Requires a [4Fe-4S] cluster for activity. In contrast to EC 4.2.1.36, homoaconitate hydratase, this enzyme can catalyse both the dehydration of (R)-homocitrate to form cis-homoaconitate and the subsequent hydration reaction that forms homoisocitrate. In addition to cis-homoaconitate, the enzyme can also catalyse the hydration of the physiological substrates dihomocitrate and trihomocitrate as well as the non-physiological substrate tetrahomocitrate. cis-Aconitate and threo-DL-isocitrate cannot act as substrates, and (S)-homocitrate and trans-homoaconitate act as inhibitors of the enzyme.
History
EC 4.2.1.114 created 2009
Pathway
Lysine biosynthesis
Methane metabolism
Metabolic pathways
Microbial metabolism in diverse environments
Biosynthesis of antibiotics
Orthology
K16792  
methanogen homoaconitase large subunit
K16793  
methanogen homoaconitase small subunit
Genes
RRS: 
RCA: 
CAU: 
CAG: 
CHL: 
HAU: 
DRA: 
DGE: 
DDR: 
DMR: 
DGO: 
DPD: 
DSW: 
DCH: 
DAB: 
DPU: 
TRA: 
TTH: 
TTJ: 
TTS: 
TTL: 
TSC: 
THC: 
TOS: 
TAQ: 
TPAR: 
MRB: 
MRE: 
MSV: 
OPR: 
MHD: 
MJA: 
MFE: 
MVU: 
MFS: 
MIF: 
MJH: 
MIG: 
MMP: 
MMQ: 
MMX: 
MMZ: 
MMD: 
MMAK: 
MMAO: 
MAE: 
MVN: 
MVO: 
MOK: 
MAC: 
MA_1223(leuC) MA_3085(leuC) MA_3751(leuD)
MBA: 
MBY: 
MBW: 
MBAR: 
MMA: 
MMAZ: 
MVC: 
MEK: 
MLS: 
METM: 
MEF: 
MEQ: 
MSJ: 
MSZ: 
MSW: 
MTHE: 
MTHR: 
MHOR: 
MBU: 
MMET: 
MMH: 
MEV: 
MZH: 
MPY: 
MHZ: 
MTP: 
MCJ: 
MCON_0444(leuC1) MCON_1922(leuD1)
MHI: 
MHU: 
MLA: 
MEM: 
MBG: 
BN140_1716(leuD3) BN140_1717(leuC3)
MEMA: 
MPI: 
MBN: 
MFO: 
MPL: 
MPD: 
MEZ: 
Mtc_1558(leuD-2) Mtc_1559(leuC-2)
RCI: 
RCIX2645(leuD-2) RCIX2646(leuC-2)
MTH: 
MMG: 
METC: 
MST: 
Msp_0374(leuD2) Msp_1100(leuC2)
MSI: 
MRU: 
mru_0384(aksD) mru_1689(aksE)
MEB: 
Abm4_0180(aksD) Abm4_0514(aksE)
MMIL: 
sm9_1773(aksE) sm9_2161(aksD)
MEYE: 
MEL: 
MEW: 
METH: 
MBMB1_0289(leuC2) MBMB1_0696(leuD1)
MFC: 
BRM9_1499(aksE) BRM9_1986(aksD)
MFI: 
MFV: 
MKA: 
MK1206(leuD_2) MK1208(leuC_2)
 » show all
Taxonomy
Reference
1  [PMID:18765671]
  Authors
Drevland RM, Jia Y, Palmer DR, Graham DE
  Title
Methanogen homoaconitase catalyzes both hydrolyase reactions in coenzyme B biosynthesis.
  Journal
J. Biol. Chem. 283 (2008) 28888-96.
  Sequence
Other DBs
ExplorEnz - The Enzyme Database: 
IUBMB Enzyme Nomenclature: 
ExPASy - ENZYME nomenclature database: 
BRENDA, the Enzyme Database: 

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