title: Divergent binding sites in pyruvate kinases I and II from Escherichia coli.
abstract: Pyridoxal 5'-phosphate incorporation into pyruvate kinase II from E. coli was decreased by the substrate phosphoenolpyruvate and increased by the allosteric activator ribose 5-phosphate, the total incorporation being linearly related to inactivation. Four lysyl residues were substantially modified, whatever the incubation conditions were while two additional residues became reactive only in the presence of the allosteric activator. Six tryptic peptides containing modified lysines were purified and sequenced. They defined five regions of pyruvate kinase II, since one of them contained two labelled lysines and included a peptide which also appeared independently. Sequence comparison with E. coli type I, yeast and cat muscle pyruvate kinases shows that the binding regions of pyruvate kinase II are clearly divergent from those of pyruvate kinase I and of the eukaryotic enzymes.
authors.affiliation: Dipartimento di Biochimica, Università di Pavia.
authors.forename: G
authors.initials: G
authors.lastname: Valentini
authors.forename: M
authors.initials: M
authors.lastname: Stoppini
authors.forename: P
authors.initials: P
authors.lastname: Iadarola
authors.forename: M
authors.initials: M
authors.lastname: Malcovati
authors.forename: G
authors.initials: G
authors.lastname: Ferri
authors.forename: M L
authors.initials: ML
authors.lastname: Speranza
mesh_terms: D000494:Allosteric Regulation; D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D002415:Cats; D002851:Chromatography, High Pressure Liquid; D004926:Escherichia coli / Q000201:enzymology*; D008969:Molecular Sequence Data; D010728:Phosphoenolpyruvate / Q000494:pharmacology; D011732:Pyridoxal Phosphate / Q000494:pharmacology; D011770:Pyruvate Kinase / Q000737:chemistry / Q000378:metabolism*; D012267:Ribosemonophosphates / Q000494:pharmacology; D016415:Sequence Alignment; D015003:Yeasts / Q000201:enzymology
chemical_list: D012267:Ribosemonophosphates; C031626:ribose-5-phosphate; D011732:Pyridoxal Phosphate; D010728:Phosphoenolpyruvate; D011770:Pyruvate Kinase