http://purl.uniprot.org/keywords/89 | http://www.w3.org/2000/01/rdf-schema#comment | "Protein binding covalently at least one linear tetrapyrrole chromophore, e.g. bilirubin, biliverdin, bilifuscin, biliprasin, choleprasin, bilihumin, and bilicyanin. Bile pigments are produced by breaking down protoporphyrin IX derived from hemoglobin and other heme proteins."xsd:string |