title: Structure of Pisum sativum Rubisco with bound ribulose 1,5-bisphosphate.
abstract: The first structure of a ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) from a pulse crop is reported. Rubisco was purified from Pisum sativum (garden pea) and diffraction-quality crystals were obtained by hanging-drop vapour diffusion in the presence of the substrate ribulose 1,5-bisphosphate. X-ray diffraction data were recorded to 2.20 Å resolution from a single crystal at the Canadian Light Source. The overall quaternary structure of non-activated P. sativum Rubisco highlights the conservation of the form I Rubisco hexadecameric complex. The electron density places the substrate in the active site at the interface of the large-subunit dimers. Lys201 in the active site is not carbamylated as expected for this non-activated structure. Some heterogeneity in the small-subunit sequence is noted, as well as possible variations in the conformation and contacts of ribulose 1,5-bisphosphate in the large-subunit active sites. Overall, the active-site conformation most closely correlates with the `closed' conformation observed in other substrate/inhibitor-bound Rubisco structures.
authors.affiliation: Department of Microbiology, University of Manitoba, 418 Buller Building, Winnipeg, MB R3T 2N2, Canada.
authors.forename: Peter C
authors.initials: PC
authors.lastname: Loewen
authors.forename: Allison L
authors.initials: AL
authors.lastname: Didychuk
authors.forename: Jacek
authors.initials: J
authors.lastname: Switala
authors.forename: Rosa
authors.initials: R
authors.lastname: Perez-Luque
authors.forename: Ignacio
authors.initials: I
authors.lastname: Fita
authors.forename: Michele C
authors.initials: MC
authors.lastname: Loewen
mesh_terms: D020134:Catalytic Domain; D018360:Crystallography, X-Ray; D008239:Lysine / Q000737:chemistry / Q000378:metabolism; D008958:Models, Molecular; D018532:Pisum sativum / Q000201:enzymology*; D010940:Plant Proteins / Q000737:chemistry / Q000378:metabolism; D011487:Protein Conformation; D055503:Protein Multimerization; D012273:Ribulose-Bisphosphate Carboxylase / Q000737:chemistry* / Q000378:metabolism*; D012274:Ribulosephosphates / Q000737:chemistry / Q000378:metabolism*
chemical_list: D010940:Plant Proteins; D012274:Ribulosephosphates; C001933:ribulose-1,5 diphosphate; D012273:Ribulose-Bisphosphate Carboxylase; D008239:Lysine