title: Allosteric inhibitor specificity of Thermotoga maritima 3-deoxy-D-arabino-heptulosonate 7-phosphate synthase.
abstract: 3-Deoxy-D-arabino-heptulosonate 7-phosphate synthase (DAH7PS) catalyses the first step of the shikimate pathway for the biosynthesis of aromatic amino acids. Allosteric regulation of Thermotoga maritima DAH7PS is mediated by L-Tyr binding to a discrete ACT regulatory domain appended to a core catalytic (β/α)8 barrel. Variants of T. maritima DAH7PS (TmaDAH7PS) were created to probe the role of key residues in inhibitor selection. Substitution Ser31Gly severely reduced inhibition by L-Tyr. In contrast both L-Tyr and L-Phe inhibited the TmaHis29Ala variant, while the variant where Ser31 and His29 were interchanged (His29Ser/Ser31His), was inhibited to a greater extent by L-Phe than L-Tyr. These studies highlight the role and importance of His29 and Ser31 for determining both inhibitory ligand selectivity and the potency of allosteric response by TmaDAH7PS.
authors.affiliation: Biomolecular Interaction Centre and Department of Chemistry, University of Canterbury, Christchurch, New Zealand.
authors.forename: Penelope J
authors.initials: PJ
authors.lastname: Cross
authors.forename: Emily J
authors.initials: EJ
authors.lastname: Parker
mesh_terms: D010723:3-Deoxy-7-Phosphoheptulonate Synthase / Q000037:antagonists & inhibitors / Q000737:chemistry* / Q000235:genetics; D000494:Allosteric Regulation; D019943:Amino Acid Substitution; D001426:Bacterial Proteins / Q000037:antagonists & inhibitors / Q000737:chemistry* / Q000235:genetics; D057075:Enzyme Assays; D007700:Kinetics; D062105:Molecular Docking Simulation; D016297:Mutagenesis, Site-Directed; D010649:Phenylalanine / Q000737:chemistry*; D011485:Protein Binding; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000235:genetics; D013329:Structure-Activity Relationship; D020124:Thermotoga maritima / Q000737:chemistry* / Q000201:enzymology; D014443:Tyrosine / Q000737:chemistry*
chemical_list: D001426:Bacterial Proteins; D011994:Recombinant Proteins; D014443:Tyrosine; D010649:Phenylalanine; D010723:3-Deoxy-7-Phosphoheptulonate Synthase
keywords: 1,3-bis[tris(hydroxymethyl)methylamino]propane; 3-deoxy-d-arabino-heptulosonate 7-phosphate; 3-deoxy-d-arabino-heptulosonate 7-phosphate synthase; ACT domain; Allosteric regulation; BTP; DAH7P; DAH7PS; DAHPS; E4P; PDB; PEG; SAXS; Shikimate pathway; d-erythrose 4-phosphate; polyethylene glycol; protein data bank; small angle X-ray scattering