1999 Fiscal Year Final Research Report Summary
Studies on translation mechanisms of plastid mRNAs
| Project/Area Number |
09304074
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| Research Category |
Grant-in-Aid for Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
植物生理
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| Research Institution | Nagoya University |
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Principal Investigator |
SUGIURA Masahiro Nagoya University, Center for Gene Research, Professor, 遺伝子実験施設, 教授 (80027044)
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| Co-Investigator(Kenkyū-buntansha) |
HIROSE Tetsuro Nagoya University, Center for Gene Research, Assistant Professor, 遺伝子実験施設, 助手 (30273220)
SUGITA Mamoru Nagoya University, Graduate School of Human Informatics, Professor, 人間情報学研究所, 教授 (70154474)
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| Project Period (FY) |
1997 – 1999
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| Keywords | tobacco / chloroplast / translation / RNA editing / initiation codon / cistron / in vitro / mRNA |
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| Research Abstract |
We found following molecular mechanisms of translation in chloroplasts using in vitro systems from isolated tobacco chloroplasts.
(1) Determination of initiation codons.
The tobacco chloroplast ndhD mRNA has three possible intiation codons. We determined the AUG triplet created from ACG by RNA editing the initiation codon. Then, GUG was found to be the initiation codon of psbC mRNA which has AUG and GUG triplets in-frame.
(2) Efficiency of initiation codons
The efficiency of translation was determined to be in the order of AUG, GUG and UUG.
(3) Translation of dicistronic mRNAs
The psaC-ndhD mRNA was found not to be translated but did after intercistronic cleavage. On the other hand, the psbD-psbC mRNA was translated as it is.
(4) Effect of the Shine-Dalgarno (SD) sequence
The SD sequence was found to be functional only when this is located 5-12 nucleotide upstream from AUG.
(5) Relationship between RNA editing and translation
We have succeeded in developing an in vitro RNA editing system from isolated tobacco chloroplasts, and proved that the edited AUG functions as an initiation codon.
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