6c3b

Publication Abstract from PubMed

Enzymes that catalyze hydroxylation of unactivated carbons normally contain heme and nonheme iron cofactors. By contrast, how a pyridoxal phosphate (PLP)-dependent enzyme could catalyze such a hydroxylation was unknown. Here, we investigate RohP, a PLP-dependent enzyme that converts l-arginine to (S)-4-hydroxy-2-ketoarginine. We determine that the RohP reaction consumes oxygen with stoichiometric release of H2O2. To understand this unusual chemistry, we obtain approximately 1.5 A resolution structures that capture intermediates along the catalytic cycle. Our data suggest that RohP carries out a four-electron oxidation and a stereospecific alkene hydration to give the (S)-configured product. Together with our earlier studies on an O2, PLP-dependent l-arginine oxidase, our work suggests that there is a shared pathway leading to both oxidized and hydroxylated products from l-arginine.

Snapshots of the Catalytic Cycle of an O2, Pyridoxal Phosphate-Dependent Hydroxylase.,Hedges JB, Kuatsjah E, Du YL, Eltis LD, Ryan KS ACS Chem Biol. 2018 Feb 28. doi: 10.1021/acschembio.8b00039. PMID:29466666^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.