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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 | 2008/05 |
| 形態種別 | 研究論文 |
| 査読 | 査読あり |
| 標題 | Structural basis of actin recognition and arginine ADP-ribosylation by Clostridium perfringens L-toxin |
| 執筆形態 | その他 |
| 掲載誌名 | PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA |
| 出版社・発行元 | NATL ACAD SCIENCES |
| 巻・号・頁 | 105(21),pp.7399-7404 |
| 担当区分 | 筆頭著者,責任著者 |
| 著者・共著者 | Hideaki Tsuge,Masahiro Nagahama,Masataka Oda,Shinobu Iwamoto,Hiroko Utsunomiya,Victor E. Marquez,Nobuhiko Katunuma,Mugio Nishizawa,Jun Sakurai |
| 概要 | The ADP-ribosylating toxins (ADPRTs) produced by pathogenic bacteria modify intracellular protein and affect eukaryotic cell function. Actin-specific ADPRTs (including Clostridium perfringens L-toxin and Clostridium botulinun C2 toxin) ADP-ribosylate G-actin at Arg-177, leading to disorganization of the cytoskeleton and cell death. Although the structures of many actin-specific ADPRTs are available, the mechanisms underlying actin recognition and selective ADP-ribosylation of Arg-177 remain unknown. Here we report the crystal structure of actin-la in complex with the nonhydrolyzable NAD analog beta TAD at 2.8 angstrom resolution. The structure indicates that la recognizes actin via five loops around NAD: loop I (Tyr-60-Tyr-62 in the N domain), loop II (active-site loop), loop III, loop IV (PN loop), and loop V (ADP-ribosylating turn-turn loop). We used site-directed mutagenesis to confirm that loop I on the N domain and loop II are essential for the ADP-ribosyltransferase activity. Furthermore, we revealed that Glu-378 on the EXE loop is in close proximity to Arg-177 in actin, and we proposed that the ADP-ribosylation of Arg-177 proceeds by an SN1 reaction via first an oxocarbenium ion intermediate and second a cationic intermediate by alleviating the strained conformation of the first oxocarbenium ion. Our results suggest a common reaction mechanism for ADPRTs. Moreover, the structure might be of use in rational drug design to block toxin-substrate recognition. |
| DOI | 10.1073/pnas.0801215105 |
| ISSN | 0027-8424 |