EGLN1 gene is located on chromosome 1, location 229568054-229627413. Gene spans 61293 bases and has 5 exons.

PHD2 expression is strongly induced in hypoxia by the HIF-1α transcription factor. Primary transcript length is 5936 bases. On mRNA level two splice variants have been proposed, lacking exons 3 or 4, but these have not been confirmed on protein level.

PHD2 protein is 426 amino acids long and approximately 46 kDa. It has a zf-MYND domain (aa 21-58) and a 2-OG-FeII-oxygenase domain (aa205-391).

Ubiquitous.

Predominantly cytoplasmic.

PHD2 is a member of the 2-oxoglutarate-dependent, non-haem iron binding dioxygenases.
PHD2 post-translationally regulates the levels of hypoxia-inducible factor-α (HIF-α) subunits in normoxic conditions by hydroxylating them in an oxygen-dependant manner on specific proline residues. This enables recognition of HIF by the VHL ubiquitin ligase complex and subsequent degradation of HIF by the proteasome. In hypoxic conditions the hydroxylation is significantly decreased, and the HIF-α subunits are stabilized. PHD2 is considered the main HIF-1α regulator in normoxic and mildly hypoxic conditions.

EGLN1 has two paralogs: EGLN2 and EGLN3 Homologs have been found in all multicellular organisms investigated.

Homozygous deletion confers embryonic lethality in mouse.

Heterozygous mutations have been associated with familial erythrocytosis. Currently three point mutations: G1112A ->Arg371His, C950G -> Pro317Arg, C1129T-> Gln377X, one deletion: 606delG -> frameshift, and one insertion: 840_841insA -> frameshift have been reported.