Egl nine homolog 3 (Egln3)

Plays a crucial role in DNA damage response (DDR) by hydroxylating TELO2, boosting its interaction with ATR which is necessary for activation of the ATR/CHK1/p53 pathway (By similarity). Cellular oxygen sensor that catalyzes, under normoxic conditions, the post-translational formation of 4-hydroxyproline in hypoxia-inducible factor (HIF) alpha cells.

Hydroxylates a particular proline found in each of the oxygen-dependent degradation (ODD) domains (N-terminal, NODD, and C-terminal, CODD) of HIF1A. Has a preference for the CODD website for both HIF1A and HIF2A.