| http://purl.uniprot.org/keywords/535 | http://www.w3.org/2000/01/rdf-schema#comment | "Protein involved in nitrogen fixation, the reduction of gaseous nitrogen to ammonia. This process is carried out only by prokaryotes who are either free-living or form symbiotic associations with plants or other organisms (e.g. termites, protozoa)."xsd:string |