ジャーナル: Nat Struct Mol Biol / 年: 2011 タイトル: Structure of green-type Rubisco activase from tobacco. 著者: Mathias Stotz / Oliver Mueller-Cajar / Susanne Ciniawsky / Petra Wendler / F Ulrich Hartl / Andreas Bracher / Manajit Hayer-Hartl / 要旨: Rubisco, the enzyme that catalyzes the fixation of atmospheric CO(2) in photosynthesis, is subject to inactivation by inhibitory sugar phosphates. Here we report the 2.95-Å crystal structure of ...Rubisco, the enzyme that catalyzes the fixation of atmospheric CO(2) in photosynthesis, is subject to inactivation by inhibitory sugar phosphates. Here we report the 2.95-Å crystal structure of Nicotiana tabacum Rubisco activase (Rca), the enzyme that facilitates the removal of these inhibitors. Rca from tobacco has a classical AAA(+)-protein domain architecture. Although Rca populates a range of oligomeric states when in solution, it forms a helical arrangement with six subunits per turn when in the crystal. However, negative-stain electron microscopy of the active mutant R294V suggests that Rca functions as a hexamer. The residues determining species specificity for Rubisco are located in a helical insertion of the C-terminal domain and probably function in conjunction with the N-domain in Rubisco recognition. Loop segments exposed toward the central pore of the hexamer are required for the ATP-dependent remodeling of Rubisco, resulting in the release of inhibitory sugar.
Protocol: Rigid body. A module of alpha helical domain and alpha-beta domain of neighbouring subunit was overlaid with p97 D2 (3CF3) structure and the hexamer was fitted into the EM map
精密化
空間: REAL / プロトコル: RIGID BODY FIT 当てはまり具合の基準: Local minimisation, fit in map
得られたモデル
PDB-3zw6: MODEL OF HEXAMERIC AAA DOMAIN ARRANGEMENT OF GREEN-TYPE RUBISCO ACTIVASE FROM TOBACCO.