title: Crystallization and preliminary crystallographic analysis of latent, active and recombinantly expressed aurone synthase, a polyphenol oxidase, from Coreopsis grandiflora.
abstract: Aurone synthase (AUS), a member of a novel group of plant polyphenol oxidases (PPOs), catalyzes the oxidative conversion of chalcones to aurones. Two active cgAUS1 (41.6 kDa) forms that differed in the level of phosphorylation or sulfation as well as the latent precursor form (58.9 kDa) were purified from the petals of Coreopsis grandiflora. The differing active cgAUS1 forms and the latent cgAUS1 as well as recombinantly expressed latent cgAUS1 were crystallized, resulting in six different crystal forms. The active forms crystallized in space groups P2(1)2(1)2(1) and P12(1)1 and diffracted to ∼ 1.65 Å resolution. Co-crystallization of active cgAUS1 with 1,4-resorcinol led to crystals belonging to space group P3(1)21. The crystals of latent cgAUS1 belonged to space group P12(1)1 and diffracted to 2.50 Å resolution. Co-crystallization of recombinantly expressed pro-AUS with the hexatungstotellurate(VI) salt Na6[TeW6O24] within the liquid-liquid phase separation zone significantly improved the quality of the crystals compared with crystals obtained without hexatungstotellurate(VI).
authors.affiliation: Institut für Biophysikalische Chemie, Fakultät für Chemie, Universität Wien, Althanstrasse 14, 1090 Wien, Austria.
authors.forename: Christian
authors.initials: C
authors.lastname: Molitor
authors.affiliation: Institut für Biophysikalische Chemie, Fakultät für Chemie, Universität Wien, Althanstrasse 14, 1090 Wien, Austria.
authors.forename: Stephan Gerhard
authors.initials: SG
authors.lastname: Mauracher
authors.affiliation: Institut für Biophysikalische Chemie, Fakultät für Chemie, Universität Wien, Althanstrasse 14, 1090 Wien, Austria.
authors.forename: Annette
authors.initials: A
authors.lastname: Rompel
mesh_terms: D001572:Benzofurans / Q000737:chemistry* / Q000378:metabolism; D004156:Catechol Oxidase / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism; D031945:Coreopsis / Q000737:chemistry* / Q000201:enzymology; D003460:Crystallization; D018360:Crystallography, X-Ray; D035264:Flowers / Q000737:chemistry / Q000201:enzymology; D007527:Isoenzymes / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D010940:Plant Proteins / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism; D012118:Resorcinols / Q000737:chemistry*; D017973:Tungsten Compounds / Q000737:chemistry
chemical_list: D001572:Benzofurans; D007527:Isoenzymes; D010940:Plant Proteins; D012118:Resorcinols; D017973:Tungsten Compounds; C486837:aurone; D004156:Catechol Oxidase; C031389:resorcinol
keywords: aurone synthase; latent proenzyme; liquid–liquid phase separation; polyoxometalate; polyphenol oxidase