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ツゲ ヒデアキ
TSUGE HIDEAKI
津下 英明 所属 京都産業大学 生命科学部 先端生命科学科 職種 教授 |
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| 言語種別 | 英語 |
| 発行・発表の年月 | 2005/07 |
| 形態種別 | その他 |
| 査読 | 査読あり |
| 標題 | Crystal structure of the NAD biosynthetic enzyme quinolinate synthase |
| 執筆形態 | その他 |
| 掲載誌名 | JOURNAL OF BIOLOGICAL CHEMISTRY |
| 出版社・発行元 | AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC |
| 巻・号・頁 | 280(29),pp.26645-26648 |
| 著者・共著者 | H Sakuraba,H Tsuge,K Yoneda,N Katunuma,T Ohshima |
| 概要 | A gene encoding a quinolinate synthase has been identified in the hyperthermophilic archaeon Pyrococcus horikoshii via genome sequencing. The gene was overexpressed in Escherichia coli, and the crystal structure of the produced enzyme was determined to 2.0 angstrom resolution in the presence of malate, a substrate analogue. The overall structure exhibits a unique triangular architecture composed of a 3-fold repeat of three-layer (alpha beta alpha) sandwich folding. Although some aspects of the fold homologous to the each domain have been observed previously, the overall structure of quinolinate synthase shows no similarity to any known protein structure. The three analogous domains are related to a pseudo-3-fold symmetry. The active site is located at the interface of the three domains and is centered on the pseudo-3-fold axis. The malate molecule is tightly held near the bottom of the active site cavity. The model of the catalytic state during the first condensation step of the quinolinate synthase reaction indicates that the elimination of inorganic phosphate from dihydroxyacetone phosphate may precede the condensation reaction. |
| DOI | 10.1074/jbc.C500192200 |
| ISSN | 0021-9258 |