intramolecular oxidoreductase activity, transposing C=C bonds prostaglandin-A1 delta-isomerase activity https://github.com/geneontology/go-ontology/issues/30193 prostaglandin A isomerase activity GO:0050219 Catalysis of the reaction: prostaglandin A1 = prostaglandin C1. MetaCyc:PROSTAGLANDIN-A1-DELTA-ISOMERASE-RXN EC:5.3.3.9 KEGG_REACTION:R04565 molecular_function prostaglandin-A1 D-isomerase activity RHEA:10460 (13E)-(15S)-15-hydroxy-9-oxoprosta-10,13-dienoate delta10-delta11-isomerase activity