イーストミトコンドリアのtRNATrpは,ナンセンスコドンUGAを認識することができます
Nature
|June 19, 1980
まとめ
ミトコンドリアはUGAコドン (通常はストップ信号) を用いてトリプトファンをコードする. UCAアンチコドンを持つ特定の酵母ミトコンドリアのtRNATrpは,UGAがトリプトファン挿入を指示することを確認し,ミトコンドリアの遺伝子コードを明確にします.
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DNA (mtDNA) 配列解析は,標準のストップコドンであるUGAがミトコンドリアにおける感覚コドンとして機能することを示唆しています.
- 牛のミトコンドリアサイトクローム酸化酵素IIサブユニットのような予測されたおよび既知のタンパク質配列のホモロジーは,UGAがトリプトファンを指定する可能性があることを示しています.
研究 の 目的:
- ミトコンドリアの遺伝子コードにおけるUGAコドンの機能を調査する.
- UGAがトリプトファンをタンパク質に組み込むことを指定しているかどうかを確認します.
主な方法:
- イーストとヒトのミトコンドリア遺伝子のDNA配列分析 (サイトクローム酸化酵素亜単位II).
- イーストミトコンドリアのtRNATrpの分離.
- pBR322-ミトコンドリアDNA再結合体におけるミトコンドリアtRNATrpの遺伝子マッピング.
- ミトコンドリアのtRNATrp遺伝子のDNAシーケンシング.
主要な成果:
- イーストとヒトのミトコンドリア遺伝子は,UGAコードンをフレームに含んでいます.
- イーストミトコンドリアのtRNATrpを分離し,その遺伝子の配列を解析した.
- ミトコンドリアのtRNATrpアンチコドンは5'UCA3'として特定されました.
- アンチコドンの揺れる位置にあるUは,UGAコドンの認識を可能にします.
結論:
- UGAコードンは,酵母ミトコンドリアのトリプトファンの感覚コードンとして使用されます.
- 5'UCA3'アンチコドンを持つミトコンドリアのtRNATrpは,UGAコドンを直接翻訳する.
- この発見は,非標準的なミトコンドリアの遺伝子コードの重要な側面を明らかにします.
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