2003 Fiscal Year Final Research Report Summary
X-ray crystallography of maturation and aminoacylation of transfer RNA
| Project/Area Number |
14580668
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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 |
Biophysics
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| Research Institution | Tokyo Institute of Technology (2003)
The University of Tokyo (2002) |
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Principal Investigator |
NUREKI Osamu Tokyo Institute of Technology, Department of Bioscience and Biotechnology, Professor, 大学院・生命理工学研究科, 教授 (10272460)
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| Project Period (FY) |
2002 – 2003
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| Keywords | X-ray crystallography / transfer RNA / RNA processing / post-transcriptional modification / aminoacyl-tRNA synthetase / apoptosis |
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| Research Abstract |
We solved crystal structures of several enzymes involved in tRNA maturation and post-transcriptional modification and their complex with tRNA. In the processing step, 3'-extended trailer sequence is trimmed by RNase PH, and, if RNase PH trims off a part of the amino-acid-attaching CCA terminus of tRNA, then CCA-adding enzyme (template-independent RNA polymerase) repairs the CCA sequence. Crystal structure of Aquifex aeolicus RNase PH at 2.3 Å resolution) reveals how two enzyme families have evolved to polymerize defined CCA trinucleotides without aid of any nucleic-acid template. In the post-transcriptional modification process, crystal structure (3.3 Å resolution) of archaeosine tRNA guanine transglycosylase in a complex with tRNA uncovered how the enzyme recognizes and modifies a deeply-buried nucleotide by deformation of canonical tRNA L-shape to 1 -shape. The 1.85 Å-resolution crystal structure of tRNA(gm18)methyltransferase revealed that the deep knot structure found in the catalytic fold not only constructs active-site and cofactor-binding site but also facilitates RNA-dependent methylation mechanism via molecular dimerization. For aminoacyl-tRNA synthetase, we elucidated the structural basis for the cytokine activity of human tryptophanyl-tRNA synthetase by crystallographic analysis, which has been gained in the long evolution of the enzyme.
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Research Products
(14 results)
