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  2. DNA topoisomerase I, mitochondrial

DNA topoisomerase I, mitochondrial

Definition

Releases the supercoiling and torsional tension of DNA introduced during duplication of mitochondrial DNA by transiently cleaving and rejoining one strand of the DNA duplex. Introduces a single-strand break via transesterification at a target site in duplex DNA. The scissile phosphodiester is attacked by the catalytic tyrosine of the enzyme, resulting in the formation of a DNA-(3'-phosphotyrosyl)-enzyme intermediate and the expulsion of a 5'-OH DNA strand. The free DNA strand then rotates around the intact phosphodiester bond on the opposing strand, thus removing DNA supercoils. Finally, in the religation step, the DNA 5'-OH attacks the covalent intermediate to expel the active-site tyrosine and restore the DNA phosphodiester backbone (By similarity).

生物医学辞典

生物医学辞典は、生物学の学術用語と専門データの包括的で専門的なデータベースです。すべての説明は、権威ある書籍や高いIFの文献に基づいており、知りたい生物医学用語の正確な説明を得ることができます。
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