E. coli のアミノアシル-tRNA合成酵素は,酵母ミトコンドリア酵素の機能を in vivo で置き換えることができます
1Department of Biology, Massachusetts Institute of Technology, Cambridge 02139.
Cell
|November 20, 1987
まとめ
研究者は,トランスファーRNA (tRNA) を充電する細菌の酵素を発現することによって,酵母に呼吸を回復させた. これは,細菌の酵素が,配列の違いにもかかわらず,酵母チロシンtRNAを認識し,機能できることを示しています.
科学分野:
- 分子生物学は分子生物学である.
- 遺伝学 遺伝学とは
- バイオケミストリー バイオケミストリー
背景:
- ミトコンドリアの機能は,タンパク質合成のための特定のアミノアシル-tRNA合成酵素に依存しています.
- 酵母菌のミトコンドリアチロシル-tRNA合成酵素 (TyrRS) は呼吸に不可欠です.
- 呼吸欠乏酵母菌株は,ミトコンドリアのタンパク質機能を研究するためのモデルを提供します.
研究 の 目的:
- エシェリキヤ大腸チロシル-tRNA合成酵素 (EcTyrRS) とサッカロミケス・セレヴィセアミトコンドリアの機能的互換性を調査する.
- EcTyrRSが,内生的なミトコンドリア TyrRSが欠けている酵母における呼吸器の欠陥を救済できるかどうかを判断する.
- EcTyrRS.のターゲティングと機能におけるミトコンドリアインポート配列の役割を評価する.
主な方法:
- イーストミトコンドリアのインポート配列でEcTyrRSをコードする遺伝子融合を構成する.
- 融合遺伝子の発現は,呼吸に欠陥のある酵母菌株で示される.
- 生物化学的および遺伝的測定を用いて呼吸機能とタンパク質の局所化を評価する.
主要な成果:
- EcTyrRS融合タンパク質の発現は,機能的なミトコンドリア TyrRS.を欠いている酵母における呼吸を回復させた.
- 融合タンパク質は,酵母ミトコンドリアにうまくインポートされました.
- ミトコンドリアの輸入は,酵母由来配列によって媒介され,呼吸器の欠陥を救うために決定的でした.
- 配列の相違にもかかわらず,EcTyrRSはミトコンドリア内の酵母チロシンtRNAを効果的に充電しました.
結論:
- 細菌のチロシル-tRNA合成酵素は,酵母ミトコンドリア内で機能することができます.
- ミトコンドリアのインポートシグナルが保存され,種を超えて機能します.
- この研究は,チロシル-tRNA合成酵素に対する基板認識能力が,これまで考えられていたよりも広いことを示唆している.
- この研究は,種間タンパク質ターゲティングとミトコンドリアの機能的補完に関する洞察を提供します.
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02:36Transfer RNA Synthesis
One of the unique features of tRNA is the presence of modified bases. In some tRNAs, modified bases account for nearly 20% of the total bases in the molecule. Altogether, these unusual bases protect the tRNA from enzymatic degradation by RNases.
Each of these chemical modifications is carried by a specific enzyme, post-transcription. All of these enzymes have unique base and site-specificity. Methylation, the most common chemical modification, is carried by at least nine different enzymes, with...
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