title: Crystallization and preliminary X-ray diffraction analysis of the catalytic subunit of ADP-glucose pyrophosphorylase from potato tuber.
abstract: ADP-glucose pyrophosphorylase is the key regulatory enzyme in the biosynthesis of starch in plants and glycogen in bacteria. The enzyme from potato tuber is comprised of a regulatory subunit and a catalytic subunit and is present as a heterotetramer (alpha(2)beta(2)). The catalytic subunit from potato tuber (50 kDa) was crystallized in four different forms, two of which are suitable for structural studies. A tetragonal crystal form obtained in the presence of the substrate analog Cr-ATP diffracted to 2.2 A and belongs to space group P4(1) (or its enantiomorph), with unit-cell parameters a = b = 110.57, c = 190.14 A. A second crystal form obtained diffracted to 2.8 A and belongs to space group P2, with unit-cell parameters a = 80.06, b = 138.84, c = 92.20 A, beta = 112. 40 degrees. As this protein displays no significant homology to any currently known protein structure, a search for heavy-atom derivatives has been initiated.
authors.affiliation: Department of Biochemistry, Michigan State University, East Lansing, MI 48824, USA.
authors.forename: K
authors.initials: K
authors.lastname: Binderup
authors.forename: L
authors.initials: L
authors.lastname: Watanabe
authors.forename: I
authors.initials: I
authors.lastname: Polikarpov
authors.forename: J
authors.initials: J
authors.lastname: Preiss
authors.forename: R K
authors.initials: RK
authors.lastname: Arni
mesh_terms: D000251:Adenosine Triphosphatases / Q000378:metabolism; D020134:Catalytic Domain; D003460:Crystallization; D051599:Glucose-1-Phosphate Adenylyltransferase; D006868:Hydrolysis; D009713:Nucleotidyltransferases / Q000737:chemistry* / Q000378:metabolism; D010940:Plant Proteins / Q000737:chemistry* / Q000378:metabolism; D011198:Solanum tuberosum / Q000201:enzymology*; D014961:X-Ray Diffraction
chemical_list: D010940:Plant Proteins; D009713:Nucleotidyltransferases; D051599:Glucose-1-Phosphate Adenylyltransferase; D000251:Adenosine Triphosphatases