日本結晶学会誌
Online ISSN : 1884-5576
Print ISSN : 0369-4585
52 巻 , 1 号
選択された号の論文の26件中1~26を表示しています
特集 構造生物学研究の新展開
1.タンパク質構造研究に対する結晶学の役割
  • 月原 冨武, 田之倉 優, 三木 邦夫
    2010 年 52 巻 1 号 p. 2
    発行日: 2010/02/28
    公開日: 2011/02/25
    ジャーナル フリー
  • 月原 冨武
    2010 年 52 巻 1 号 p. 3-7
    発行日: 2010/02/28
    公開日: 2011/02/25
    ジャーナル フリー
    Structural studies on membrane proteins have been performed at atomic level by both three-dimensional X-ray crystallography and two-dimensional electron crystallography in Japan as in Europe and Unites States. More than 13 membrane protein structures were elucidate by X-ray method in our country, and seven membrane protein structures were determined by cryo-electron microscopic method developed by Fujiyoshi of Kyoto University. Extensive crystallographic studies on calcium pump and cytochrome c oxidase elucidated their functional mechanisms at atomic level.
    Structure and switching mechanism of a flagellum were studied by X-ray and electron microscopic methods. Vault structure exhibiting D39 symmetry was determined by X-ray method.
  • 田之倉 優, 永田 宏次, 宮園 健一, 宮川 拓也, 岡井 公彦
    2010 年 52 巻 1 号 p. 8-13
    発行日: 2010/02/28
    公開日: 2011/02/25
    ジャーナル フリー
    Structural biology has made tremendous progress in this decade. Here we briefly introduce the Target Proteins Research Program, a national project promoted by the Ministry of Education, Culture, Sports, Science and Technology (MEXT) of Japan. The program aims to reveal the structure and function of proteins that are of great importance in both academic research and industrial application. We also summarize the results of structure-function analyses of (i) transcriptional regulatory proteins useful for the breading of drought and heat stress tolerant crops, (ii) useful enzymes for the production of chiral compounds, and (iii) useful enzymes for the degradation of environmental pollution substances. These results can be utilized in various areas of industries, to enhance food production, to improve the efficiency of pharmaceutical compound production, and to promote the bioremediation of contaminated soil and water.
  • 竹田 一旗, 平野 優, 三木 邦夫
    2010 年 52 巻 1 号 p. 14-18
    発行日: 2010/02/28
    公開日: 2011/02/25
    ジャーナル フリー
    Many protein structures have been determined by X-ray crystallography and deposited with the Protein Data Bank. However, these structures at usual resolution (1.5<d<3.0 Å) are insufficient in their precision and quantity for elucidating the molecular mechanism of protein functions directly from structural information. Several studies at ultra-high resolution (d<0.8 Å) have been performed with synchrotron radiation in the last decade. The highest resolution of the protein crystals was achieved at 0.54 Å resolution for a small protein, crambin. In such high resolution crystals, almost all of hydrogen atoms of proteins and some hydrogen atoms of bound water molecules are experimentally observed. In addition, outer-shell electrons of proteins can be analyzed by the multipole refinement procedure. However, the influence of X-rays should be precisely estimated in order to derive meaningful information from the crystallographic results. In this review, we summarize refinement procedures, current status and perspectives for ultra high resolution protein crystallography.
2.基礎研究から応用展開に向けて
(a)包括的構造生物学基礎研究
  • 岩田 想
    2010 年 52 巻 1 号 p. 19
    発行日: 2010/02/28
    公開日: 2011/02/25
    ジャーナル フリー
  • 深井 周也, 佐藤 裕介
    2010 年 52 巻 1 号 p. 20-24
    発行日: 2010/02/28
    公開日: 2011/02/25
    ジャーナル フリー
    Ubiquitin is a conserved 76-residue protein that is reversibly conjugated with substrate proteins to regulate various cellular processes. The terminal carboxyl group of ubiquitin can be bonded to lysine residues of substrate proteins including ubiquitin itself. All seven lysine residues (K6, K11, K27, K29, K33, K48 and K63) and the N-terminal Met can act as receptors for the conjugation, producing polyubiquitin chains. For instance, the most abundant K48-linked chains serve as signals for proteasomal degradation, whereas K63-linked chains function in other proteasome-independent processes. Here we show how these functionally and structurally distinct chains are discriminated by linkage-specific deubiquitinating enzymes and binding proteins.
  • 前田 将司
    2010 年 52 巻 1 号 p. 25-30
    発行日: 2010/02/28
    公開日: 2011/02/25
    ジャーナル フリー
    Here we describe the long awaited atomic structure of the gap junction channel. The structure reveals intra-/inter- monomer interactions, which stabilize the channel structure, and intercellular interactions between two apposing hemichannels. The structure also reveals the pore structure in detail, charge distribution, pore-lining residues and so on. The novel structure, pore funnel, is found on the top of the pore and the relationship with channel gating could be inspected.
  • 加藤 博章, 佐藤 友美, 上口(田中) 美弥子
    2010 年 52 巻 1 号 p. 31-36
    発行日: 2010/02/28
    公開日: 2011/02/25
    ジャーナル フリー
    Gibberellins (GAs) are phytohormones essential for many developmental processes in plants. We analyzed the crystal structure of a nuclear GA receptor, GIBBERELLIN INSENSITIVE DWARF 1 (GID1) from Oryza sativa. As it was proposed from the sequence similarity, the overall structure of GID1 shows an α/β-hydrolase fold similar to that of the hormone-sensitive lipases (HSLs) except for an amino-terminal lid. The GA-binding site corresponds to the substrate-binding site of HSLs. Almost residues assigned for GA binding showed very little or no activity when they were replaced with Ala. The substitution of the residues corresponding to those of the lycophyte GID1s caused an increase in the binding affinity for GA34, a 2β-hydroxylated GA4. These findings indicate that GID1 originated from HSL and was tinkered to have the specificity for bioactive GAs in the course of plant evolution.
  • 箱嶋 敏雄, 村瀬 浩司, 平野 良憲, Tai-ping SUN
    2010 年 52 巻 1 号 p. 37-41
    発行日: 2010/02/28
    公開日: 2011/02/25
    ジャーナル フリー
    Gibberellins control a diverse range of growth and developmental processes in higher plants and have been widely utilized in the agricultural industry. By binding to a nuclear receptor GIBBERELLIN INSENSITIVE DWARF1 (GID1), gibberellins regulate gene expression by promoting degradation of the transcriptional regulator DELLA proteins. The precise manner in which GID1 discriminates and becomes activated by bioactive gibberellins for specific binding to DELLA proteins remains unclear. We present the crystal structure of a ternary complex of Arabidopsis thaliana GID1A, a bioactive gibberellin and the N-terminal DELLA domain of GAI. In this complex, GID1a occludes gibberellin in a deep binding pocket covered by its N-terminal helical switch region, which in turn interacts with the DELLA domain containing DELLA, VHYNP and LExLE motifs. Our results establish a structural model of a plant hormone receptor which is distinct from the hormone-perception mechanism and effector recognition of the known auxin receptors.
(b)技術開発型研究
(c)応用指向型研究
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