title: Amino acid biosynthesis: new architectures in allosteric enzymes.
abstract: This review focuses on the allosteric controls in the Aspartate-derived and the branched-chain amino acid biosynthetic pathways examined both from kinetic and structural points of view. The objective is to show the differences that exist among the plant and microbial worlds concerning the allosteric regulation of these pathways and to unveil the structural bases of this diversity. Indeed, crystallographic structures of enzymes from these pathways have been determined in bacteria, fungi and plants, providing a wonderful opportunity to obtain insight into the acquisition and modulation of allosteric controls in the course of evolution. This will be examined using two enzymes, threonine synthase and the ACT domain containing enzyme aspartate kinase. In a last part, as many enzymes in these pathways display regulatory domains containing the conserved ACT module, the organization of ACT domains in this kind of allosteric enzymes will be reviewed, providing explanations for the variety of allosteric effectors and type of controls observed.
authors.affiliation: Laboratoire de Physiologie Cellulaire Végétale, Université Joseph Fourier, Commissariat à l'Energie Atomique, Institut de Recherche et de Technologie des Sciences du Vivant, 38054 Grenoble, France.
authors.forename: Gilles
authors.initials: G
authors.lastname: Curien
authors.forename: Valérie
authors.initials: V
authors.lastname: Biou
authors.forename: Corine
authors.initials: C
authors.lastname: Mas-Droux
authors.forename: Mylène
authors.initials: M
authors.lastname: Robert-Genthon
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Ferrer
authors.forename: Renaud
authors.initials: R
authors.lastname: Dumas
mesh_terms: D000494:Allosteric Regulation; D000596:Amino Acids / Q000096:biosynthesis*; D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism; D019757:Carbon-Oxygen Lyases / Q000737:chemistry / Q000378:metabolism; D004798:Enzymes / Q000737:chemistry / Q000378:metabolism*; D008958:Models, Molecular; D010940:Plant Proteins / Q000737:chemistry / Q000378:metabolism*; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary
chemical_list: D000596:Amino Acids; D001426:Bacterial Proteins; D004798:Enzymes; D010940:Plant Proteins; D019757:Carbon-Oxygen Lyases; C023160:threonine synthase