ジャーナル: Proc Natl Acad Sci U S A / 年: 2015 タイトル: Electron crystallography of ultrathin 3D protein crystals: atomic model with charges. 著者: Koji Yonekura / Kazuyuki Kato / Mitsuo Ogasawara / Masahiro Tomita / Chikashi Toyoshima / 要旨: Membrane proteins and macromolecular complexes often yield crystals too small or too thin for even the modern synchrotron X-ray beam. Electron crystallography could provide a powerful means for ...Membrane proteins and macromolecular complexes often yield crystals too small or too thin for even the modern synchrotron X-ray beam. Electron crystallography could provide a powerful means for structure determination with such undersized crystals, as protein atoms diffract electrons four to five orders of magnitude more strongly than they do X-rays. Furthermore, as electron crystallography yields Coulomb potential maps rather than electron density maps, it could provide a unique method to visualize the charged states of amino acid residues and metals. Here we describe an attempt to develop a methodology for electron crystallography of ultrathin (only a few layers thick) 3D protein crystals and present the Coulomb potential maps at 3.4-Å and 3.2-Å resolution, respectively, obtained from Ca(2+)-ATPase and catalase crystals. These maps demonstrate that it is indeed possible to build atomic models from such crystals and even to determine the charged states of amino acid residues in the Ca(2+)-binding sites of Ca(2+)-ATPase and that of the iron atom in the heme in catalase.
RESIDUE 994 G IN THIS STRUCTURE IS NATURAL VARIATION ACCORDING TO DATABASE P04191-2 (AT2A1_RABIT) ...RESIDUE 994 G IN THIS STRUCTURE IS NATURAL VARIATION ACCORDING TO DATABASE P04191-2 (AT2A1_RABIT) ISOFORM SERCA1A. C-TERMINAL RESIDUES 994-1001 (DPEDERRK) ARE REPLACED BY G IN ISOFORM SERCA1A.
解像度: 3.4→8 Å / Cor.coef. Fo:Fc: 0.798 / Cor.coef. Fo:Fc free: 0.768 / SU B: 27.539 / SU ML: 0.5 / 交差検証法: THROUGHOUT / σ(F): 0 / ESU R Free: 0.939 / 立体化学のターゲット値: MAXIMUM LIKELIHOOD 詳細: HYDROGENS HAVE BEEN ADDED IN THE RIDING POSITIONS U VALUES: REFINED INDIVIDUALLY
Rfactor
反射数
%反射
Selection details
Rfree
0.3152
436
3 %
RANDOM
Rwork
0.2769
14184
-
-
obs
0.278
-
67.48 %
-
溶媒の処理
イオンプローブ半径: 0.8 Å / 減衰半径: 0.8 Å / VDWプローブ半径: 1.2 Å / 溶媒モデル: BABINET MODEL WITH MASK