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Molecular basis of dihydrouridine formation on tRNA
| Title: | Molecular basis of dihydrouridine formation on tRNA |
| Authors: | Yu, Futao Browse this author | | Tanaka, Yoshikazu Browse this author →KAKEN DB | | Yamashita, Keitaro Browse this author | | Suzuki, Takeo Browse this author | | Nakamura, Akiyoshi Browse this author | | Hirano, Nagisa Browse this author | | Suzuki, Tsutomu Browse this author | | Yao, Min Browse this author →KAKEN DB | | Tanaka, Isao Browse this author →KAKEN DB |
| Keywords: | protein-tRNA complex | | RNA modification | | substrate recognition | | X-ray crystallography |
| Issue Date: | 6-Dec-2011 |
| Publisher: | National Academy of Sciences |
| Journal Title: | Proceedings of the National Academy of Sciences of the United States of America |
| Volume: | 108 |
| Issue: | 49 |
| Start Page: | 19593 |
| End Page: | 19598 |
| Publisher DOI: | 10.1073/pnas.1112352108 |
| Abstract: | Dihydrouridine (D) is a highly conserved modified base found in tRNAs from all domains of life. Dihydrouridine synthase (Dus) catalyzes the D formation of tRNA through reduction of uracil base with flavin mononucleotide (FMN) as a cofactor. Here, we report the crystal structures of Thermus thermophilus Dus (TthDus), which is responsible for D formation at positions 20 and 20a, in complex with tRNA and with a short fragment of tRNA (D-loop). Dus interacts extensively with the D-arm and recognizes the elbow region composed of the kissing loop interaction between T- and D-loops in tRNA, pulling U20 into the catalytic center for reduction. Although distortion of the D-loop structure was observed upon binding of Dus to tRNA, the canonical D-loop/T-loop interaction was maintained. These results were consistent with the observation that Dus preferentially recognizes modified rather than unmodified tRNAs, indicating that Dus introduces D20 by monitoring the complete L-shaped structure of tRNAs. In the active site, U20 is stacked on the isoalloxazine ring of FMN, and C5 of the U20 uracil ring is covalently cross-linked to the thiol group of Cys93, implying a catalytic mechanism of D20 formation. In addition, the involvement of a cofactor molecule in uracil ring recognition was proposed. Based on a series of mutation analyses, we propose a molecular basis of tRNA recognition and D formation catalyzed by Dus. |
| Type: | article (author version) |
| URI: | http://hdl.handle.net/2115/49352 |
| Appears in Collections: | 創成研究機構 (Creative Research Institution) > 雑誌発表論文等 (Peer-reviewed Journal Articles, etc)
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Submitter: 田中 良和
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