##gff-version 3 Q21U92 UniProtKB Chain 1 246 . . . ID=PRO_0000290523;Note=1-(5-phosphoribosyl)-5-[(5-phosphoribosylamino)methylideneamino] imidazole-4-carboxamide isomerase Q21U92 UniProtKB Active site 8 8 . . . Note=Proton acceptor;Ontology_term=ECO:0000255;evidence=ECO:0000255|HAMAP-Rule:MF_01014 Q21U92 UniProtKB Active site 131 131 . . . Note=Proton donor;Ontology_term=ECO:0000255;evidence=ECO:0000255|HAMAP-Rule:MF_01014