title: Purine nucleoside phosphorylase variation in the brook lamprey, Lampetra planeri (Bloch) (Petromyzone, Agnatha): evidence for a trimeric enzyme structure.
abstract: Genetic evidence for a trimeric structure for purine nucleoside phosphorylase in the brook lamprey is presented. This enzyme is encoded by a single locus with two alleles segregating at frequencies of 0.98 and 0.02 in a Welsh population. It is suggested that this enzyme is likely to be a trimer in all classes of vertebrates.
mesh_terms: D000483:Alleles; D000818:Animals; D005787:Gene Frequency; D014644:Genetic Variation; D007798:Lampreys / Q000235:genetics; D046911:Macromolecular Substances; D008970:Molecular Weight; D009132:Muscles / Q000201:enzymology; D010430:Pentosyltransferases / Q000235:genetics*; D011683:Purine-Nucleoside Phosphorylase / Q000235:genetics*; D013045:Species Specificity
chemical_list: D046911:Macromolecular Substances; D010430:Pentosyltransferases; D011683:Purine-Nucleoside Phosphorylase