title: Uridine phosphorylase from Escherichia coli B. Enzymatic and molecular properties.
abstract: Uridine phosphorylase (EC 2.4.2.3) from Escherichia coli B is an oligomeric protein composed of four identical subunits of 29,000 mol. wt. The enzyme has four half-cystine residues per subunit titrable only in denaturing condition. No disulphide linkages either inter- or intra-chain are present. The isoelectric point is 5.25. The enzyme shows strict specificity toward uridine and 5-methyluridine and is inhibited by thymine, deoxycytidine and heavy metal ions.
mesh_terms: D000596:Amino Acids / Q000032:analysis; D003841:Deoxycytidine / Q000494:pharmacology; D004926:Escherichia coli / Q000201:enzymology*; D007525:Isoelectric Focusing; D008970:Molecular Weight; D010430:Pentosyltransferases / Q000302:isolation & purification*; D013056:Spectrophotometry, Ultraviolet; D013379:Substrate Specificity; D013438:Sulfhydryl Compounds / Q000032:analysis; D013941:Thymine / Q000494:pharmacology; D014543:Uridine Phosphorylase / Q000037:antagonists & inhibitors / Q000302:isolation & purification*
chemical_list: D000596:Amino Acids; D013438:Sulfhydryl Compounds; D003841:Deoxycytidine; D010430:Pentosyltransferases; D014543:Uridine Phosphorylase; D013941:Thymine