title: 3-Hydroxybenzoate:coenzyme A ligase from cell cultures of Centaurium erythraea: isolation and characterization.
abstract: In xanthone biosynthesis, 3-hydroxybenzoate:coenzyme A ligase (3HBL) supplies the starter substrate for the formation of an intermediate benzophenone. 3HBL from cell cultures of the medicinal plant Centaurium erythraea was purified to apparent homogeneity using a seven-step-procedure. The enzyme was an AMP-forming CoA ligase with a Km = 14.7 microM for 3-hydroxybenzoic acid, 8.5 microM for coenzyme A and 229 microM for ATP. The pH and temperature optima were 7.5 and 35 degrees C, respectively. In SDS-PAGE, two polypeptides of Mr 41,500 and 40,500 were detected. Both proteins were structurally related to each other as shown by tryptic digestion. Their N-termini were blocked. The difference in their apparent molecular masses could not be attributed to glycosylation. 3HBL had a native Mr of approx. 50,000 and is thus active as a monomer.
authors.affiliation: Institut für Pharmazeutische Biologie, Universität Bonn, Germany.
authors.forename: W
authors.initials: W
authors.lastname: Barillas
authors.forename: L
authors.initials: L
authors.lastname: Beerhues
mesh_terms: D000249:Adenosine Monophosphate / Q000378:metabolism; D002118:Calcium / Q000494:pharmacology; D018929:Cell Culture Techniques; D003066:Coenzyme A Ligases / Q000737:chemistry / Q000302:isolation & purification*; D004591:Electrophoresis, Polyacrylamide Gel; D004795:Enzyme Stability; D006031:Glycosylation; D006863:Hydrogen-Ion Concentration; D062385:Hydroxybenzoates / Q000737:chemistry*; D007700:Kinetics; D008274:Magnesium / Q000494:pharmacology; D008345:Manganese / Q000494:pharmacology; D008970:Molecular Weight; D010936:Plant Extracts / Q000737:chemistry / Q000302:isolation & purification; D010946:Plants, Medicinal / Q000737:chemistry* / Q000166:cytology; D013194:Staining and Labeling; D013696:Temperature; D014357:Trypsin / Q000378:metabolism
chemical_list: D062385:Hydroxybenzoates; D010936:Plant Extracts; C032948:3-hydroxybenzoic acid; D000249:Adenosine Monophosphate; D008345:Manganese; D014357:Trypsin; C411162:3-hydroxybenzoate coenzyme A ligase; D003066:Coenzyme A Ligases; D008274:Magnesium; D002118:Calcium