2000 Fiscal Year Final Research Report Summary
Molecular mechanism of processing of precursor proteins in organelles derived from parasitic organisms
| Project/Area Number |
10480171
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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 |
Functional biochemistry
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| Research Institution | KYUSHU UNIVERSITY |
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Principal Investigator |
ITO Akio Faculty of Sciences, KYUSHU UNIVERSITY Professor, 大学院・理学研究院, 教授 (30037379)
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| Co-Investigator(Kenkyū-buntansha) |
KITADA Sakae Faculty of Sciences, KYUSHU UNIVERSITY Assistant (professor), 大学院・理学研究院, 助手 (20284482)
OGISHIMA Tadasi Faculty of Sciences, KYUSHU UNIVERSITY Asssociate Professor, 大学院・理学研究院, 助教授 (70177153)
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| Project Period (FY) |
1998 – 2000
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| Keywords | processing peptidase / processing / precursor protein / mitochondria / signal recognition / parasite / X-ray analysis / peptide substrate |
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| Research Abstract |
Mechanism of processing of precursor proteins in organelles derived from parasitic organisms.
(1) Mitochondrial processing peptidase : Systematic and quantitative analyses, using various synthetic peptides based on the amino acid sequence of the extension peptides of the precursors, demonstrated that a combination of residues around the cleavage site, including the proximal arginine and residues at positions 1, 2, and 3, and the distal basic amino acids appears to be responsible for recognition of the substrates and for determination of the cleavage site by MPP.Functional amino acid residues in β-MPP were determined by site-directed mutation experiments. Shortening of the glycine-rich stretch in α-MPP led to a dramatic reduction of interaction between the enzyme and substrate peptides and cleavage reaction. Fluorescence resonance energy transfer (FRET) measurements indicate that the N-terminal portion and the portion around the cleavage site of the extension peptides interact with specific sites in the MPP molecule. The structures of recombinant yeast MPP and a cleavage-deficient mutant of MPP complexed with synthetic signal peptides were determined using X-ray crystallographic techniques.
(2) MPP-like proteases of protozoan : cDNAs of MPP-like proteases of trypanosoma was obtained and the amino acid sequence was deduced.
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