title: Catalytically active filaments - pyruvate decarboxylase from Neurospora crassa. pH-controlled oligomer structure and catalytic function.
abstract: Pyruvate decarboxylase is a key enzyme in organisms whose energy metabolism is based on alcoholic fermentation. The enzyme catalyses the nonoxidative decarboxylation of 2-oxo acids in the presence of the cofactors thiamine diphosphate and magnesium ions. Pyruvate decarboxylase species from yeasts and plant seeds studied to date are allosterically activated by their substrate pyruvate. However, detailed kinetic studies on the enzyme from Neurospora crassa demonstrate for the first time the lack of substrate activation for a yeast pyruvate decarboxylase species. The quaternary structure of this enzyme species is also peculiar because it forms filamentous structures. The complex enzyme structure was analysed using a number of methods, including small-angle X-ray solution scattering, transmission electron microscopy, analytical ultracentrifugation and size-exclusion chromatography. These measurements were complemented by detailed kinetic studies in dependence on the pH.
authors.affiliation: Division of Enzymology, Institute of Biochemistry & Biotechnology, Martin-Luther-University Halle-Wittenberg, Halle (Saale), Germany.
authors.forename: Stefanie
authors.initials: S
authors.lastname: Hüttl
authors.forename: Juliane
authors.initials: J
authors.lastname: Fiebig
authors.forename: Steffen
authors.initials: S
authors.lastname: Kutter
authors.forename: Gerd
authors.initials: G
authors.lastname: Hause
authors.forename: Hauke
authors.initials: H
authors.lastname: Lilie
authors.forename: Michael
authors.initials: M
authors.lastname: Spinka
authors.forename: Stephan
authors.initials: S
authors.lastname: König
mesh_terms: D000494:Allosteric Regulation; D002850:Chromatography, Gel; D003653:Decarboxylation; D004789:Enzyme Activation; D004795:Enzyme Stability; D005656:Fungal Proteins / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism* / Q000648:ultrastructure; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D046529:Microscopy, Electron, Transmission; D008869:Microtubule-Associated Proteins / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism* / Q000648:ultrastructure; D009492:Neurospora crassa / Q000201:enzymology*; D020836:Protein Structure, Quaternary; D011767:Pyruvate Decarboxylase / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism* / Q000648:ultrastructure; D053838:Scattering, Small Angle; D014461:Ultracentrifugation; D014961:X-Ray Diffraction
chemical_list: D005656:Fungal Proteins; D008869:Microtubule-Associated Proteins; C075721:CFP protein, Neurospora crassa; D011767:Pyruvate Decarboxylase