Involved in the biosynthesis of terminal alkyne-containing amino acids such as L-beta-ethynylserine, that are produced as antibiotics by S.cattleya. Catalyzes the hydroxylation of the dipeptide L-gamma-glutamyl-L-propargylglycine, leading to L-gamma-glutamyl-L-beta-ethynylserine. Cannot use L-propargylglycine as substrate. 2-oxoglutarate + L-gamma-glutamyl-L-propargylglycine + O2 = CO2 + L-gamma-glutamyl-(3R)-L-beta-ethynylserine + succinate Amino-acid metabolism. Antibiotic biosynthesis. Cells lacking this gene still produce L-propargylglycine but not L-beta-ethynylserine, that are terminal alkyne-containing amino acids produced by wild-type S.cattleya.