EC               Enzyme                                 

beta-carotene 15,15'-dioxygenase;
blh (gene name);
BCO1 (gene name);
BCDO (gene name);
carotene dioxygenase;
carotene 15,15'-dioxygenase;
BCMO1 (misleading);
beta-carotene 15,15'-monooxygenase (incorrect)
Acting on single donors with incorporation of molecular oxygen (oxygenases);
With incorporation of two atoms of oxygen
BRITE hierarchy
beta-carotene:oxygen 15,15'-dioxygenase (bond-cleaving)
beta-carotene + O2 = 2 all-trans-retinal [RN:R00032]
beta-carotene [CPD:C02094];
O2 [CPD:C00007]
all-trans-retinal [CPD:C00376]
Requires Fe2+. The enzyme cleaves beta-carotene symmetrically, producing two molecules of all-trans-retinal. Both atoms of the oxygen molecule are incorporated into the products [8]. The enzyme can also process beta-cryptoxanthin, 8'-apo-beta-carotenal, 4'-apo-beta-carotenal, alpha-carotene and gamma-carotene in decreasing order. The presence of at least one unsubstituted beta-ionone ring in a substrate greater than C(30) is mandatory [5]. A prokaryotic enzyme has been reported from the uncultured marine bacterium 66A03, where it is involved in the proteorhodopsin system, which uses retinal as its chromophore [6,7].
EC created 2012 (EC created 1972 as EC, transferred 2001 to EC, incorporated 2015), modified 2016
ec00830  Retinol metabolism
ec01100  Metabolic pathways
K00515  beta-carotene 15,15'-dioxygenase
K21817  beta-carotene 15,15'-dioxygenase
HSA: 53630(BCO1)
PTR: 468043(BCO1)
PPS: 100987572(BCO1)
GGO: 101132534(BCO1)
PON: 100454129(BCO1)
NLE: 100603806(BCO1)
MCC: 721412(BCO1)
MCF: 102121880(BCO1)
CSAB: 103233367(BCO1)
RRO: 104671629(BCO1)
RBB: 108539495(BCO1)
CJC: 100393264(BCO1)
SBQ: 101032680(BCO1)
MMU: 63857(Bco1)
RNO: 114106(Bco1)
CGE: 100760350(Bco1)
NGI: 103732128(Bco1)
HGL: 101724039(Bco1)
CCAN: 109696646(Bco1)
OCU: 100358087(BCO1)
TUP: 102484616(BCO1)
CFA: 489695(BCO1)
AML: 100483748(BCO1)
UMR: 103662084(BCO1)
ORO: 101377344(BCO1)
FCA: 101101606(BCO1)
PTG: 102959940(BCO1)
AJU: 106984030(BCO1)
BTA: 534696(BCO1)
BOM: 102266127(BCO1)
BIU: 109572100(BCO1)
PHD: 102315733(BCO1)
CHX: 102179507(BCO1)
OAS: 100294509(BCMO1) 101121875(BCO1)
SSC: 100192320(BCO1)
CFR: 102513983(BCO1)
CDK: 105089436(BCO1)
BACU: 103015035(BCO1)
LVE: 103072015(BCO1)
OOR: 101285979(BCO1)
ECB: 100069873(BCO1)
EPZ: 103554670(BCO1)
EAI: 106833126(BCO1)
MYB: 102263079(BCO1)
MYD: 102771959(BCO1)
HAI: 109378342(BCO1)
RSS: 109434307(BCO1)
PALE: 102897588(BCO1)
TMU: 101341485
MDO: 100031779(BCO1)
SHR: 100920512(BCO1)
OAA: 103171493(BCO1)
GGA: 395346(BCO1)
MGP: 100549225(BCO1)
CJO: 107319380(BCO1)
APLA: 101798614(BCO1)
ACYG: 106033290(BCO1)
TGU: 100228904(BCO1)
GFR: 102040064(BCO1)
FAB: 101812113(BCO1)
PHI: 102103988(BCO1)
PMAJ: 107209839(BCO1)
CCW: 104691821(BCO1)
FPG: 101914506(BCO1)
FCH: 102058462(BCO1)
CLV: 102086476(BCO1)
EGZ: 104133740(BCO1)
AAM: 106483349(BCO1)
ASN: 102378066(BCO1)
AMJ: 102573601(BCO1)
PSS: 102455966(BCO1)
CMY: 102929893(BCO1)
CPIC: 101934984(BCO1)
ACS: 100563614(bco1)
PVT: 110085493(BCO1)
GJA: 107105786(BCO1)
XLA: 108714030(bco1.L)
XTR: 100486582(bco1)
NPR: 108786164(BCO1)
DRE: 393580(bco1l) 84039(bco1)
TRU: 101076274(bco1) 101078539
NCC: 104954746 104958616(bco1)
PRET: 103457901 103482517(bco1)
LCM: 102362963(BCO1)
CMK: 103175958(bco1)
CIN: 778841(bco)
SPU: 591892
CRG: 105341121
OBI: 106882614
EPA: 110233465
PAM: PANA_1898
PAJ: PAJ_1228
PVA: Pvag_1853
MBS: MRBBS_2788(blh)
GNI: GNIT_0397
GPS: C427_1920
LHA: LHA_1128
SULJ: SJPD1_1205
MCH: Mchl_1482
MET: M446_0536
SSAN: NX02_06035
SPHR: BSY17_1104
ABG: Asbog_01119(blh)
GOB: Gobs_1772
RXY: Rxyl_2039
TAQ: TO73_1641
IPA: Isop_3504
SRU: SRU_0742(brp) SRU_2210
SRM: SRM_00919(brp) SRM_02436
SLI: Slin_1644
DOK: MED134_07114(blh)
DDO: I597_1807
NDO: DDD_0295
POM: MED152_12849(blh)
WIN: WPG_3400
HAL: VNG_1465G(brp) VNG_2136G(blh)
HSL: OE_3102R(brp) OE_3980R(blh)
HHB: Hhub_3440(blh)
HMA: rrnAC1901(brp) rrnAC2066(blh)
HHI: HAH_2414(brp) HAH_2561(blh)
NPH: NP_0206A(brp) NP_0650A(blh)
NMO: Nmlp_1292(blh) Nmlp_3577(brp)
HWA: HQ_1019A(blh) HQ_1864A(brp) HQ_2381A
HWC: Hqrw_1021(blh) Hqrw_2002(brp)
HLA: Hlac_2732
NAT: NJ7G_2814
 » show all
1  [PMID:5946623]
Goodman DS, Huang HS, Shiratori T.
Mechanism of the biosynthesis of vitamin A from beta-carotene.
J. Biol. Chem. 241 (1966) 1929-32.
Goodman, D.S., Huang, H.S., Kanai, M. and Shiratori, T.
The enzymatic conversion of all-trans beta-carotene into retinal.
J. Biol. Chem. 242 (1967) 3543-3554.
3  [PMID:11401432]
Yan W, Jang GF, Haeseleer F, Esumi N, Chang J, Kerrigan M, Campochiaro M, Campochiaro P, Palczewski K, Zack DJ
Cloning and characterization of a human beta,beta-carotene-15,15'-dioxygenase that is highly expressed in the retinal pigment epithelium.
Genomics. 72 (2001) 193-202.
[hsa:53630] [mmu:63857]
4  [PMID:11458349]
Leuenberger MG, Engeloch-Jarret C, Woggon WD.
The Reaction Mechanism of the Enzyme-Catalyzed Central Cleavage of beta-Carotene  to Retinal This research was supported by F. Hoffmann-La Roche AG and the Swiss National Science Foundation. We are grateful to F. Hoffmann-La Roche AG for a generous gift of carotenoids and Dr. Claus Bornemann for preliminary experiments.
Angew. Chem. Int. Ed. Engl. 40 (2001) 2613-2617.
5  [PMID:18979213]
Kim YS, Oh DK
Substrate specificity of a recombinant chicken beta-carotene 15,15'-monooxygenase that converts beta-carotene into retinal.
Biotechnol. Lett. 31 (2009) 403-8.
6  [PMID:19366683]
Kim YS, Kim NH, Yeom SJ, Kim SW, Oh DK
In vitro characterization of a recombinant Blh protein from an uncultured marine  bacterium as a beta-carotene 15,15'-dioxygenase.
J. Biol. Chem. 284 (2009) 15781-93.
7  [PMID:20229064]
Kim YS, Park CS, Oh DK
Retinal production from beta-carotene by beta-carotene 15,15'-dioxygenase from an unculturable marine bacterium.
Biotechnol. Lett. 32 (2010) 957-61.
8  [PMID:24668807]
dela Sena C, Riedl KM, Narayanasamy S, Curley RW Jr, Schwartz SJ, Harrison EH.
The human enzyme that converts dietary provitamin A carotenoids to vitamin A is a dioxygenase.
J. Biol. Chem. 289 (2014) 13661-6.
Other DBs
ExplorEnz - The Enzyme Database:
IUBMB Enzyme Nomenclature:
ExPASy - ENZYME nomenclature database:
BRENDA, the Enzyme Database:

DBGET integrated database retrieval system