25-Hydroxyvitamin D 1-alpha-hydroxylase (VD 1A hydroxylase) also known as calcidiol 1-monooxygenase [5]orcytochrome p450 27B1 (CYP27B1) or simply 1-alpha-hydroxylase is a cytochrome P450 enzyme that in humans is encoded by the CYP27B1 gene.[6][7][8]
calcidiol 1-monooxygenase | |||||||||
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Identifiers | |||||||||
EC no. | 1.14.15.18 | ||||||||
CAS no. | 9081-36-1 | ||||||||
Databases | |||||||||
IntEnz | IntEnz view | ||||||||
BRENDA | BRENDA entry | ||||||||
ExPASy | NiceZyme view | ||||||||
KEGG | KEGG entry | ||||||||
MetaCyc | metabolic pathway | ||||||||
PRIAM | profile | ||||||||
PDB structures | RCSB PDB PDBe PDBsum | ||||||||
Gene Ontology | AmiGO / QuickGO | ||||||||
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VD 1A hydroxylase is located in the proximal tubule of the kidney and a variety of other tissues, including skin (keratinocytes), immune cells,[9] and bone (osteoblasts).[10]
The enzyme catalyzes the hydroxylationofcalcifedioltocalcitriol (the bioactive form of Vitamin D):[11]
The enzyme is also able to oxidize ercalcidiol (25-OH D2) to ercalcitriol, secalciferol to calcitetrol, and 25-hydroxy-24-oxocalciol to (1S)-1,25-dihydroxy-24-oxocalciol.[12]
Loss-of-function mutations in CYP27B1 cause Vitamin D-dependent rickets, type IA.[13]
Click on genes, proteins and metabolites below to link to respective articles. [§ 1]