Increased Turnover at Limiting O2 Concentrations by the Thr(387) → Ala Variant of HIF-Prolyl Hydroxylase PHD2.

ABSTRACT: PHD2 is a 2-oxoglutarate, non-heme Fe(2+)-dependent oxygenase that senses O2 levels in human cells by hydroxylating two prolyl residues in the oxygen-dependent degradation domain (ODD) of HIF1α. Identifying the active site contacts that determine the rate of reaction at limiting O2 concentrations is crucial for understanding how this enzyme senses pO2 and may suggest methods for chemically altering hypoxia responses. A hydrogen bonding network extends from the Fe(II) cofactor through ordered waters to the Thr(387) residue in the second coordination sphere. Here we tested the impact of the side chain of Thr(387) on the reactivity of PHD2 toward O2 through a combination of point mutagenesis, steady state kinetic experiments and {FeNO}(7) EPR spectroscopy. The steady state kinetic parameters

SUBMITTER: Pektas S 

PROVIDER: S-EPMC4939847 | biostudies-literature | 2015 May

REPOSITORIES: biostudies-literature