2005 Fiscal Year Final Research Report Summary
Complete Structural Determination of Rice dwarf virus
| Project/Area Number |
14380319
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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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 | Osaka University |
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Principal Investigator |
NAKAGAWA Atsushi Osaka University, Institute for Protein Research, Professor, 蛋白質研究所, 教授 (20188890)
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| Co-Investigator(Kenkyū-buntansha) |
YAMASHITA Eiki Osaka University, Institute for Protein Research, Instructor, 蛋白質研究所, 助手 (00294132)
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| Project Period (FY) |
2002 – 2005
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| Keywords | Biological macromolecular assemblies / Synchrotron Radiation / Virus / Structure assembly of virus / X-ray crystal structure analysis / Infection mechanism of virus / Self-replication mechanism of virus |
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| Research Abstract |
This project has been worked on the structural studies of Rice dwarf virus, which is a double-shelled virus with its molecular mass of about 7,500 kDa, to reveal its whole structure using x-ray crystallography, cryo-electron micrograph and molecular biological techniques.
Most of the structural studies have been done with the P2-deletion RDV particle, which contained all viral components except the P2 protein, where P2 protein had been removed from the sample during treatment with CCl_4 in the purification step. The 3.5Å resolution electron density map of RDV crystal, determined by x-ray crystallography, revealed almost complete structures of the inner- and outer-shells (P3 and P8 proteins) and a part of P7 protein. The interactions between the subunit proteins suggest how the 900 protein components are built into a higher-ordered virus core structure, and we proposed the model for the hierarchy of structural assembly. This model was strongly supported by some experiments using molecular biological techniques.
Internal structure of the virus particle was studied by combination of the single-particle analysis using cryo-electron micrograph and x-ray crystallography. Low-resolution cryo-EM map showed clear molecular envelop corresponding to the transcription complex (complex of P1,P5 and P7 proteins). The map also clearly showed at lease three layered-structure of dsRNA. Especially, dsRNAs in the first and second layer showed rod-shaped structure, which are packed into liquid crystal-like structure.
In addition, we have succeeded to purify the component proteins from the virus particle and/or from overexpressed sample, these samples were subjected to crystallization to reveal the high-resolution structure of the component proteins.
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Research Products
(52 results)
