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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 | 2007/01 |
| 形態種別 | 研究論文 |
| 査読 | 査読あり |
| 標題 | Structure of a hyperthermophilic archaeal homing endonuclease, I-Tsp061I: Contribution of cross-domain polar networks to thermostability |
| 執筆形態 | その他 |
| 掲載誌名 | JOURNAL OF MOLECULAR BIOLOGY |
| 出版社・発行元 | ACADEMIC PRESS LTD ELSEVIER SCIENCE LTD |
| 巻・号・頁 | 365(2),pp.362-378 |
| 担当区分 | 最終著者,責任著者 |
| 著者・共著者 | Hitoshi Nakayama,Tatsuro Shimamura,Takahito Imagawa,Nobuaki Shirai,Takashi Itoh,Yoshihiko Sako,Masashi Miyano,Haruhiko Sakuraba,Toshihisa Ohshima,Norimichi Nomura,Hideaki Tsuge |
| 概要 | A novel LAGLIDADG-type homing endonuclease (HEase), I-TspO61I, from the hyperthermophilic archaeon Thermoproteus sp. IC-061 16 S rRNA gene (rDNA) intron was characterized with respect to its structure, catalytic properties and thermostability. It was found that I-Tsp061I is a HEase isoschizomer of the previously described I-PogI and exhibits the highest thermostability among the known LAGLIDADG-type HEases. Determination of the crystal structure of I-Tsp061I at 2.1 A resolution using the multiple isomorphous replacement and anomalous scattering method revealed that the overall fold is similar to that of other known LAGLIDADG-type HEases, despite little sequence similarity between I-TspO61I and those HEases. However, I-Tsp061I contains important cross-domain polar networks, unlike its mesophilic counterparts. Notably, the polar network Tyr6-Asp104-His180-107O-HOH12-104O-Asn177 exists across the two packed a-helices containing both the LAGLIDADG catalytic motif and the GxxxG hydrophobic helix bundle motif. Another important structural feature is the salt-bridge network Asp29-Arg31-GIu182 across N and C-terminal domain interface, which appears to contribute to the stability of the domain/domain packing. On the basis of these structural analyses and extensive mutational studies, we conclude that such cross-domain polar networks play key roles in stabilizing the catalytic center and domain packing, and underlie the hyperthermostability of T-Tsp061I. (c) 2006 Published by Elsevier Ltd. |
| DOI | 10.1016/j.jmb.2006.09.066 |
| ISSN | 0022-2836 |