UROS
UniProt:P10746 UROS
GNT1
UGT1
UGT1A1
UniProt:P22309 UGT1A1
COX10
UniProt:Q12887 COX10
COX15
UniProt:Q7KZN9 COX15
The heme ring is cleaved by heme oxygenase
ALAS condenses SUCC-CoA and Gly to form dALA
Succinyl CoA and glycine condense to form 5-aminolevulinate (ALA)
ALA is transported from the mitochondrial matrix to the cytosol
Mitochondrial dALA translocates to cytosol
ALAD binds to Pb2+
ALAD octamer associates with Pb++, forming a catalytically inactive complex
ALAD condenses 2 dALAs to form PBG
Two molecules of ALA condense to form porphobilinogen (PBG)
4 PBGs bind to form HMB
Four PBGs combine through deamination to form hydroxymethylbilane (HMB)
Conversion of HMB to uroporphyrinogen III
UROS transforms HMB to URO3
HMBL spontaneously transforms to URO1
Spontaneous conversion of HMBL to uroporphyrinogen I (URO1)
UROD decarboxylates URO3 to COPRO3
Uroporphyrinogen III is decarboxylated to form coproporphyrinogen III
UROD decarboxylates URO1 to COPRO1
Uroporphyrinogen I is decarboxylated to form coproporphyrinogen I
Cytosolic COPRO3 translocates to mitochondrial intermembrane space
Translocation of coproporphyrinogen III from the cytosol to the mitochondrial intermembrane space
CPO transforms COPRO3 to PPGEN9
Conversion of coproporphyrinogen III to protoporphyrinogen IX
Oxidation of protoporphyrinogen IX to protoporphyrin IX
PPO oxidises PPGEN9 to PRIN9
Mitochondrial intermembrane PRIN9 translocates to mitochondrial matrix
Protoporphyrin IX is transported from the mitochondrial intermembrane space into the mitochondrial matrix
FECH binds Fe2+ to PRIN9 to form heme
Ferrous iron is inserted into protoporphyrin IX to form heme
COX10 transforms heme to heme O
COX15 transforms heme O to heme A
Biliverdin is reduced to bilirubin
Bilirubin translocates from the cytosol to the ER lumen
Bilirubin forms a monoglucuronide
bilirubin + UDP-glucuronic acid => bilirubin monoglucuronide + UDP
Bilirubin monoglucuronide is conjugated to bilirubin diglucuronide
bilirubin monoglucuronide + UDP-glucuronic acid => bilirubin diglucuronide + UDP
Metabolism of porphyrins
Porphyrin metabolism
Heme biosynthesis
Heme degradation