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
ec00300  Lysine biosynthesis
ec00680  Methane metabolism
ec01100  Metabolic pathways
ec01120  Microbial metabolism in diverse environments
ec01130  Biosynthesis of antibiotics
Orthology
K16792  methanogen homoaconitase large subunit
K16793  methanogen homoaconitase small subunit
Genes
BOH: AKI39_19115
RRS: RoseRS_1053 RoseRS_1056
RCA: Rcas_3472 Rcas_3474
CAU: Caur_0329 Caur_0330(leuD)
CHL: Chy400_0354 Chy400_0355
CAG: Cagg_3601 Cagg_3602
HAU: Haur_3302 Haur_3303
DRA: DR_1610 DR_1614(leuD)
DGE: Dgeo_1154 Dgeo_1156
DDR: Deide_13460 Deide_13470
TSC: TSC_c01880(hacA) TSC_c01890(hacB)
MMD: GYY_08235
MMG: MTBMA_c02160(leuC1) MTBMA_c12270(leuD1)
MWO: MWSIV6_0177(hacA) MWSIV6_1206(hacB)
METE: tca_00796(DmdB_1) tca_01581(dmdA_2)
MST: Msp_0374(leuD2) Msp_1100(leuC2)
MRU: mru_0384(aksD) mru_1689(aksE)
MEB: Abm4_0180(aksD) Abm4_0514(aksE)
MMIL: sm9_1773(aksE) sm9_2161(aksD)
METH: MBMB1_0289(leuC2) MBMB1_0696(leuD1)
MFC: BRM9_1499(aksE) BRM9_1986(aksD)
MFI: DSM1535_0178(leuC2) DSM1535_2193(leuD1)
MCUB: MCBB_0567(hacA) MCBB_0707(hacB)
MKA: MK1206(leuD_2) MK1208(leuC_2)
CDIV: CPM_1676
MAC: MA_1223(leuC) MA_3085(leuC) MA_3751(leuD)
MBU: Mbur_1578 Mbur_2263(hacA)
MCJ: MCON_0444(leuC1) MCON_1922(leuD1)
MBG: BN140_1716(leuD3) BN140_1717(leuC3)
MEMA: MMAB1_2209(leuC)
MEZ: Mtc_1558(leuD-2) Mtc_1559(leuC-2)
RCI: RCIX2645(leuD-2) RCIX2646(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 283:28888-96 (2008)
DOI:10.1074/jbc.M802159200
  Sequence
Other DBs
ExplorEnz - The Enzyme Database: 4.2.1.114
IUBMB Enzyme Nomenclature: 4.2.1.114
ExPASy - ENZYME nomenclature database: 4.2.1.114
BRENDA, the Enzyme Database: 4.2.1.114

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