2006 Fiscal Year Final Research Report Summary
Molecular Evolution of RNA modification enzymes and RNA recognition mechanism
| Project/Area Number |
17613003
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
極限環境生物学
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| Research Institution | Ehime University |
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Principal Investigator |
HORI Hiroyuki Ehime University, Associate Professor, 理工学研究科, 助教授 (20256960)
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| Co-Investigator(Kenkyū-buntansha) |
TAKAI Kazuyuki Ehime University, Associate Professor, 無細胞生命科学工学研究センター, 助教授 (40260848)
NUREKI Osamu Tokyo Institute of Technology, Professor, 生命理工学研究科, 教授 (10272460)
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| Project Period (FY) |
2005 – 2006
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| Keywords | Nucleic Acid / Enzyme / Genome / Evolution / Biomolecule |
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| Research Abstract |
In this project, we have obtained many findings in the RNA modification field.
Main findings are as follows.
(1) Construction of in vitro RNA modification system under high temperatures
We have clarified roles of thermophilic-bacteria specific polyamines against the RNA modification machinery.
(2) Clarifications of RNA recognition mechanisms of RNA modification enzymes
We have reported that Aquifex aeolicus TrmD [tRNA (m1 G37) methyltransferase] has a unique RNA recognition mechanism.
The enzyme methylates tRNA molecules possessing not only G36G37 sequence but also A36G37 sequence. Furthermore, the enzyme methylates micro-helix RNA possessing A36G37 sequence. These results showed that A. aeolicus TrmD has a broad substarte specificity in comparison with other TrmD proteins.
We have reported that eukaryote tRNA (m7G46) methyltransferase [Trm8/Trm82 complex] recognizes the D-arm structure in tRNA, demonstrating that eukaryote enzyme has a strict RNA recognition mechanism as compared to bacterial enzymes.
(3) Clarifications of relationship between protein structure and RNA recognition mechanism
We performed site-directed mutagenesis study against basic amino acid residues conserved in TrmH [tRNA (Gm18) methyltransferases]. We could distinguish residues required in the first tRNA binding process and residues required in the progress of the catalytic cycles.
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