title: Allosteric Communication Disrupted by a Small Molecule Binding to the Imidazole Glycerol Phosphate Synthase Protein-Protein Interface.
abstract: Allosteric enzymes regulate a wide range of catalytic transformations, including biosynthetic mechanisms of important human pathogens, upon binding of substrate molecules to an orthosteric (or active) site and effector ligands at distant (allosteric) sites. We find that enzymatic activity can be impaired by small molecules that bind along the allosteric pathway connecting the orthosteric and allosteric sites, without competing with endogenous ligands. Noncompetitive allosteric inhibitors disrupted allostery in the imidazole glycerol phosphate synthase (IGPS) enzyme from Thermotoga maritima as evidenced by nuclear magnetic resonance, microsecond time-scale molecular dynamics simulations, isothermal titration calorimetry, and kinetic assays. The findings are particularly relevant for the development of allosteric antibiotics, herbicides, and antifungal compounds because IGPS is absent in mammals but provides an entry point to fundamental biosynthetic pathways in plants, fungi, and bacteria.
authors: Univ Lyon, ENS de Lyon, CNRS, Université Claude Bernard Lyon 1 , Laboratoire de Chimie UMR 5182, F-69342 Lyon, France.
authors: Ivan
authors: I
authors: Rivalta
authors: George P
authors: GP
authors: Lisi
authors: Ning-Shiuan
authors: NS
authors: Snoeberger
authors: Gregory
authors: G
authors: Manley
authors: J Patrick
authors: JP
authors: Loria
authors: Victor S
authors: VS
authors: Batista
mesh_terms: D000494:Allosteric Regulation; D000495:Allosteric Site; D000619:Aminohydrolases / Q000737:chemistry / Q000378:metabolism*; D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism*; D001665:Binding Sites; D055162:Biocatalysis; D002151:Calorimetry / Q000379:methods; D020134:Catalytic Domain; D018360:Crystallography, X-Ray; D007093:Imidazoles / Q000737:chemistry / Q000378:metabolism; D008024:Ligands; D009682:Magnetic Resonance Spectroscopy; D056004:Molecular Dynamics Simulation; D011485:Protein Binding; D000072417:Protein Domains; D021122:Protein Subunits / Q000737:chemistry / Q000378:metabolism; D012265:Ribonucleotides / Q000737:chemistry / Q000378:metabolism; D054852:Small Molecule Libraries / Q000737:chemistry / Q000378:metabolism*; D020124:Thermotoga maritima / Q000201:enzymology
chemical_list: D001426:Bacterial Proteins; D007093:Imidazoles; D008024:Ligands; D021122:Protein Subunits; D012265:Ribonucleotides; D054852:Small Molecule Libraries; C081348:N(1)-((5'-phosphoribulosyl)formimino)-5-aminoimidazo-4-carboxamide ribonucleotide; C087227:imidazole glycerol phosphate synthase; D000619:Aminohydrolases