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heme b

362,296 routes · scope human · up to 3 steps · built 5 October 2026 · Reactions · API

Inferred

Every route here is a hypothesis drawn from reference reactions (Rhea and Human-GEM), not a finding. Currency species such as water, ATP and NAD(H) never form a step. Evidence key

147 compounds within 3 steps: 6 in 1, 11 in 2, 130 in 3

Does it reach a compound?

One step

COReach from here →
1. Heme Oxygenase 1
Catalysed by HMOX1, HMOX2cytosolOne of 2 routes
iron(2+)Reach from here →
1. Heme Oxygenase 1
Catalysed by HMOX1, HMOX2cytosolOne of 2 routes
deoxyhemoglobinReach from here →
1. globin to hemoglobin conversion
No catalyst recordedcytosol
biliverdin IXalphaReach from here →
1. Heme Oxygenase 1
Catalysed by HMOX1, HMOX2cytosolOne of 2 routes
Fe(II)-heme oReach from here →
1. farnesyl-PP[m] + H2O[m] + heme[m] = PPi[m] + Fe(II)-heme o[m]
Catalysed by COX10mitochondrial matrixOne of 4 routes
ferroheme c di-L-cysteine(2-) residueReach from here →
1. Cytochrome c apocytochrome-c-lyase
Catalysed by HCCSmitochondrial matrix

Two steps

bilirubin IXalphaReach from here →
1. Heme Oxygenase 1
2. Bilirubin:NAD+ oxidoreductase
Catalysed by HMOX1, HMOX2, BLVRB, BLVRAcytosolOne of 2 routes
AH2Reach from here →
1. farnesyl-PP[m] + H2O[m] + heme[m] = PPi[m] + Fe(II)-heme o[m]
2. Fe(II)-heme o + 2 A + H2O = Fe(II)-heme a + 2 AH2
Catalysed by COX10, COX15mitochondrial matrix
(2E,6E)-farnesyl diphosphate

Three steps

CHEBI:1146900Reach from here →
Catalysed by HMOX1, HMOX2, NDUFAB1, FDXR and 5 morecytosol, mitochondrial matrix
N(omega)-methyl-L-arginineReach from here →
Catalysed by and 6 more

Page 1 of 3

Reach from here →

farnesyl-PP[m] + H2O[m] + heme[m] = PPi[m] + Fe(II)-heme o[m]
heme b + (2E,6E)-farnesyl diphosphate + H2O = Fe(II)-heme o + diphosphate

Catalysed by COX10mitochondrial matrix

Fe(3+)Reach from here →

Heme Oxygenase 1
Fe(II):oxygen oxidoreductase

Catalysed by HMOX1, HMOX2, CP, FTH1 and 3 morecytosol, extracellular spaceOne of 4 routes

di-mu-sulfido-diiron(2+)Reach from here →

Heme Oxygenase 1
De novo synthesis of 2Fe2S

Catalysed by HMOX1, HMOX2, NDUFAB1, FDXR and 5 morecytosol, mitochondrial matrix

1,2-dihydroxy-5-(methylsulfanyl)pent-1-en-3-oneReach from here →

Heme Oxygenase 1
1,2-dihydroxy-5-(methylsulfanyl)pent-1-en-3-one + O2 = 3-(methylsulfanyl)propanoate + CO + formate + 2 H(+)

Catalysed by HMOX1, HMOX2, ADI1cytosol

globinReach from here →

globin to hemoglobin conversion
heme oxygenase (biliverdin-producing) (hemoglobin)

Catalysed by HMOX1, HMOX2cytosol

quercetinReach from here →

Heme Oxygenase 1
quercetin + O2 = 2-(3,4-dihydroxybenzoyloxy)-4,6-dihydroxybenzoate + CO

Catalysed by HMOX1, HMOX2, PIRcytosol

L-alanineReach from here →

Heme Oxygenase 1
De novo synthesis of 2Fe2S

Catalysed by HMOX1, HMOX2, NDUFAB1, FDXR and 5 morecytosol, mitochondrial matrix

(4Z,15Z)-bilirubin IXalphaReach from here →

Heme Oxygenase 1
(4Z,15Z)-bilirubin IXalpha + NADP(+) = biliverdin IXalpha + NADPH + H(+)

Catalysed by HMOX1, HMOX2, BLVRAcytosolOne of 2 routes

Fe(II)-heme aReach from here →

farnesyl-PP[m] + H2O[m] + heme[m] = PPi[m] + Fe(II)-heme o[m]
Fe(II)-heme o + 2 A + H2O = Fe(II)-heme a + 2 AH2

Catalysed by COX10, COX15mitochondrial matrix

cytosol, mitochondrial matrix

isopentenyl diphosphateReach from here →

farnesyl-PP[m] + H2O[m] + heme[m] = PPi[m] + Fe(II)-heme o[m]
heme b + (2E,6E)-farnesyl diphosphate + H2O = Fe(II)-heme o + diphosphate
isopentenyl diphosphate + (2E)-geranyl diphosphate = (2E,6E)-farnesyl diphosphate + diphosphate

Catalysed by COX10, GGPS1, FDPSmitochondrial matrix

(8S)-3',8-cyclo-7,8-dihydroguanosine 5'-triphosphateReach from here →

farnesyl-PP[m] + H2O[m] + heme[m] = PPi[m] + Fe(II)-heme o[m]
Fe(II)-heme o + 2 A + H2O = Fe(II)-heme a + 2 AH2
GTP + AH2 + S-adenosyl-L-methionine = (8S)-3',8-cyclo-7,8-dihydroguanosine 5'-triphosphate + 5'-deoxyadenosine + L-methionine + A + H(+)

Catalysed by COX10, COX15, MOCS1mitochondrial matrix

AReach from here →

farnesyl-PP[m] + H2O[m] + heme[m] = PPi[m] + Fe(II)-heme o[m]
Fe(II)-heme o + 2 A + H2O = Fe(II)-heme a + 2 AH2
A + NADH + H(+) = AH2 + NAD(+)

Catalysed by COX10, COX15, AIFM1, PYROXD1mitochondrial matrixOne of 70 routes

(18S)-hydroxy-(5Z,8Z,11Z,14Z,16E)-eicosapentaenoateReach from here →

farnesyl-PP[m] + H2O[m] + heme[m] = PPi[m] + Fe(II)-heme o[m]
Fe(II)-heme o + 2 A + H2O = Fe(II)-heme a + 2 AH2
(5Z,8Z,11Z,14Z,17Z)-eicosapentaenoate + AH2 + O2 = (18S)-hydroxy-(5Z,8Z,11Z,14Z,16E)-eicosapentaenoate + A + H2O

Catalysed by COX10, COX15, PTGS2mitochondrial matrix

(15S)-hydroxy-(5Z,8Z,11Z,13E,17Z)-eicosapentaenoateReach from here →

farnesyl-PP[m] + H2O[m] + heme[m] = PPi[m] + Fe(II)-heme o[m]
Fe(II)-heme o + 2 A + H2O = Fe(II)-heme a + 2 AH2
(5Z,8Z,11Z,14Z,17Z)-eicosapentaenoate + AH2 + O2 = (15S)-hydroxy-(5Z,8Z,11Z,13E,17Z)-eicosapentaenoate + A + H2O

Catalysed by COX10, COX15, PTGS2mitochondrial matrix

prostaglandin H3Reach from here →

farnesyl-PP[m] + H2O[m] + heme[m] = PPi[m] + Fe(II)-heme o[m]
Fe(II)-heme o + 2 A + H2O = Fe(II)-heme a + 2 AH2
prostaglandin G3 + AH2 = prostaglandin H3 + A + H2O

Catalysed by COX10, COX15, PTGS2mitochondrial matrix

13-hydroxy-(9Z,11E)-octadecadienoateReach from here →

farnesyl-PP[m] + H2O[m] + heme[m] = PPi[m] + Fe(II)-heme o[m]
Fe(II)-heme o + 2 A + H2O = Fe(II)-heme a + 2 AH2
(9Z,12Z)-octadecadienoate + AH2 + O2 = 13-hydroxy-(9Z,11E)-octadecadienoate + A + H2O

Catalysed by COX10, COX15, PTGS2mitochondrial matrix

9-hydroxy-(10E,12Z)-octadecadienoateReach from here →

farnesyl-PP[m] + H2O[m] + heme[m] = PPi[m] + Fe(II)-heme o[m]
Fe(II)-heme o + 2 A + H2O = Fe(II)-heme a + 2 AH2
(9Z,12Z)-octadecadienoate + AH2 + O2 = 9-hydroxy-(10E,12Z)-octadecadienoate + A + H2O

Catalysed by COX10, COX15, PTGS2mitochondrial matrix

2,4-dinitrophenyl-S-glutathioneReach from here →

Heme Oxygenase 1
Bilirubin:NAD+ oxidoreductase
transport of bilirubin (cytosol to extracellular)

Catalysed by HMOX1, HMOX2, BLVRB, BLVRA and 2 morecytosol, extracellular spaceOne of 2 routes

(13R)-hydroxy-(9Z,11E)-octadecadienoateReach from here →

farnesyl-PP[m] + H2O[m] + heme[m] = PPi[m] + Fe(II)-heme o[m]
Fe(II)-heme o + 2 A + H2O = Fe(II)-heme a + 2 AH2
(9Z,12Z)-octadecadienoate + AH2 + O2 = (13R)-hydroxy-(9Z,11E)-octadecadienoate + A + H2O

Catalysed by COX10, COX15, PTGS1, PTGS2mitochondrial matrix

2-[(11R)-hydroxy-(5Z,8Z,12E,14Z)-eicosatetraenoyl]-sn-glycero-3-phosphocholineReach from here →

farnesyl-PP[m] + H2O[m] + heme[m] = PPi[m] + Fe(II)-heme o[m]
Fe(II)-heme o + 2 A + H2O = Fe(II)-heme a + 2 AH2
2-(5Z,8Z,11Z,14Z)-eicosatetraenoyl-sn-glycero-3-phosphocholine + AH2 + O2 = 2-[(11R)-hydroxy-(5Z,8Z,12E,14Z)-eicosatetraenoyl]-sn-glycero-3-phosphocholine + A + H2O

Catalysed by COX10, COX15, PTGS2mitochondrial matrix

2-[(15R)-hydroxy-(5Z,8Z,11Z,13E)-eicosatetraenoyl]-sn-glycero-3-phosphocholineReach from here →

farnesyl-PP[m] + H2O[m] + heme[m] = PPi[m] + Fe(II)-heme o[m]
Fe(II)-heme o + 2 A + H2O = Fe(II)-heme a + 2 AH2
2-(5Z,8Z,11Z,14Z)-eicosatetraenoyl-sn-glycero-3-phosphocholine + AH2 + O2 = 2-[(15R)-hydroxy-(5Z,8Z,11Z,13E)-eicosatetraenoyl]-sn-glycero-3-phosphocholine + A + H2O

Catalysed by COX10, COX15, PTGS2mitochondrial matrix

2-[(15S)-hydroxy-(5Z,8Z,11Z,13E)-eicosatetraenoyl]-sn-glycero-3-phosphocholineReach from here →

farnesyl-PP[m] + H2O[m] + heme[m] = PPi[m] + Fe(II)-heme o[m]
Fe(II)-heme o + 2 A + H2O = Fe(II)-heme a + 2 AH2
2-(5Z,8Z,11Z,14Z)-eicosatetraenoyl-sn-glycero-3-phosphocholine + AH2 + O2 = 2-[(15S)-hydroxy-(5Z,8Z,11Z,13E)-eicosatetraenoyl]-sn-glycero-3-phosphocholine + A + H2O

Catalysed by COX10, COX15, PTGS2mitochondrial matrix

2-(prostaglandin H2)-sn-glycero-3-phosphoethanolamineReach from here →

farnesyl-PP[m] + H2O[m] + heme[m] = PPi[m] + Fe(II)-heme o[m]
Fe(II)-heme o + 2 A + H2O = Fe(II)-heme a + 2 AH2
2-(prostaglandin G2)-sn-glycero-3-phosphoethanolamine + AH2 = 2-(prostaglandin H2)-sn-glycero-3-phosphoethanolamine + A + H2O

Catalysed by COX10, COX15, PTGS2mitochondrial matrix

2-(prostaglandin H2)-sn-glycero-3-phosphocholineReach from here →

farnesyl-PP[m] + H2O[m] + heme[m] = PPi[m] + Fe(II)-heme o[m]
Fe(II)-heme o + 2 A + H2O = Fe(II)-heme a + 2 AH2
2-(prostaglandin G2)-sn-glycero-3-phosphocholine + AH2 = 2-(prostaglandin H2)-sn-glycero-3-phosphocholine + A + H2O

Catalysed by COX10, COX15, PTGS2mitochondrial matrix

3-(methylthio)propionic acidReach from here →

Heme Oxygenase 1
1,2-dihydroxy-5-(methylsulfanyl)pent-1-en-3-one + O2 = 3-(methylsulfanyl)propanoate + CO + formate + 2 H(+)
acireductone dioxygenase

Catalysed by HMOX1, HMOX2, ADI1cytosol

pyruvateReach from here →

Heme Oxygenase 1
De novo synthesis of 2Fe2S
(R)-3-Amino-2-methylpropanoate:pyruvate aminotransferase

Catalysed by HMOX1, HMOX2, NDUFAB1, FDXR and 6 morecytosol, mitochondrial matrixOne of 14 routes

squaleneReach from here →

farnesyl-PP[m] + H2O[m] + heme[m] = PPi[m] + Fe(II)-heme o[m]
heme b + (2E,6E)-farnesyl diphosphate + H2O = Fe(II)-heme o + diphosphate
Squalene Synthase

Catalysed by COX10, FDFT1mitochondrial matrix, endoplasmic reticulumOne of 3 routes

CHEBI:15570Reach from here →

Heme Oxygenase 1
De novo synthesis of 2Fe2S
alanine racemase

Catalysed by HMOX1, HMOX2, NDUFAB1, FDXR and 5 morecytosol, mitochondrial matrix

L-leucineReach from here →

Heme Oxygenase 1
De novo synthesis of 2Fe2S
transport of alanine and leucine (cytosol to extracellular)

Catalysed by HMOX1, HMOX2, NDUFAB1, FDXR and 6 morecytosol, mitochondrial matrix, extracellular spaceOne of 4 routes

CHEBI:15699Reach from here →

Heme Oxygenase 1
De novo synthesis of 2Fe2S
transport of alanine and homoserine (cytosol to extracellular)

Catalysed by HMOX1, HMOX2, NDUFAB1, FDXR and 6 morecytosol, mitochondrial matrix, extracellular spaceOne of 3 routes

formateReach from here →

Heme Oxygenase 1
1,2-dihydroxy-5-(methylsulfanyl)pent-1-en-3-one + O2 = 3-(methylsulfanyl)propanoate + CO + formate + 2 H(+)
1,2-dihydroxy-5-(methylsulfanyl)pent-1-en-3-one + O2 = 3-(methylsulfanyl)propanoate + CO + formate + 2 H(+)

Catalysed by HMOX1, HMOX2, ADI1cytosolOne of 2 routes

CHEBI:15971Reach from here →

Heme Oxygenase 1
De novo synthesis of 2Fe2S
transport of alanine and histidine (cytosol to extracellular)

Catalysed by HMOX1, HMOX2, NDUFAB1, FDXR and 6 morecytosol, mitochondrial matrix, extracellular spaceOne of 2 routes

L-cystineReach from here →

Heme Oxygenase 1
De novo synthesis of 2Fe2S
Transport of L-Cystine (L-Alanine antiport) by B0, +At Transporter

Catalysed by HMOX1, HMOX2, NDUFAB1, FDXR and 7 morecytosol, mitochondrial matrix, extracellular space

cob(II)alaminReach from here →

farnesyl-PP[m] + H2O[m] + heme[m] = PPi[m] + Fe(II)-heme o[m]
Fe(II)-heme o + 2 A + H2O = Fe(II)-heme a + 2 AH2
2 cob(II)alamin + A + 2 H2O + 2 H(+) = 2 aquacob(III)alamin + AH2

Catalysed by COX10, COX15, MTRRmitochondrial matrix

(R)-3-aminoisobutyric acidReach from here →

Heme Oxygenase 1
De novo synthesis of 2Fe2S
(R)-3-Amino-2-methylpropanoate:pyruvate aminotransferase

Catalysed by HMOX1, HMOX2, NDUFAB1, FDXR and 6 morecytosol, mitochondrial matrix

L-citrullineReach from here →

Heme Oxygenase 1
De novo synthesis of 2Fe2S
transport of alanine and citrulline (cytosol to extracellular)

Catalysed by HMOX1, HMOX2, NDUFAB1, FDXR and 6 morecytosol, mitochondrial matrix, extracellular spaceOne of 2 routes

iodideReach from here →

farnesyl-PP[m] + H2O[m] + heme[m] = PPi[m] + Fe(II)-heme o[m]
Fe(II)-heme o + 2 A + H2O = Fe(II)-heme a + 2 AH2
3,3',5'-triiodo-L-thyronine + iodide + A + H(+) = L-thyroxine + AH2

Catalysed by COX10, COX15, DIO1, DIO3mitochondrial matrixOne of 22 routes

L-valineReach from here →

Heme Oxygenase 1
De novo synthesis of 2Fe2S
transport of alanine and valine (cytosol to extracellular)

Catalysed by HMOX1, HMOX2, NDUFAB1, FDXR and 6 morecytosol, mitochondrial matrix, extracellular spaceOne of 6 routes

L-arginineReach from here →

Heme Oxygenase 1
De novo synthesis of 2Fe2S
transport of alanine and arginine (cytosol to extracellular)

Catalysed by HMOX1, HMOX2, NDUFAB1, FDXR and 6 morecytosol, mitochondrial matrix, extracellular spaceOne of 3 routes

nitric oxideReach from here →

farnesyl-PP[m] + H2O[m] + heme[m] = PPi[m] + Fe(II)-heme o[m]
Fe(II)-heme o + 2 A + H2O = Fe(II)-heme a + 2 AH2
2 nitrite + AH2 + 2 H(+) = 2 nitric oxide + A + 2 H2O

Catalysed by COX10, COX15, SUOXmitochondrial matrix