1I7D

NONCOVALENT COMPLEX OF E.COLI DNA TOPOISOMERASE III WITH AN 8-BASE SINGLE-STRANDED DNA OLIGONUCLEOTIDE

1I7D の概要

• エントリーDOI: 10.2210/pdb1i7d/pdb
• 分子名称: 5'-D(*CP*GP*CP*AP*AP*CP*TP*T)-3', DNA TOPOISOMERASE III, CHLORIDE ION, ... (5 entities in total)
• 機能のキーワード: dna topoisomerase, decatenating enzyme, protein-dna complex, single-stranded dna, isomerase-dna complex, isomerase/dna
• 由来する生物種: Escherichia coli
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 76653.79

構造登録者

Changela, A.,DiGate, R.J.,Mondragon, A. (登録日: 2001-03-08, 公開日: 2001-06-29, 最終更新日: 2023-08-09)

主引用文献

Changela, A.,DiGate, R.J.,Mondragon, A.
Crystal structure of a complex of a type IA DNA topoisomerase with a single-stranded DNA molecule.
Nature, 411:1077-1081, 2001

PubMed Abstract: A variety of cellular processes, including DNA replication, transcription, and chromosome condensation, require enzymes that can regulate the ensuing topological changes occurring in DNA. Such enzymes-DNA topoisomerases-alter DNA topology by catalysing the cleavage of single-stranded DNA (ssDNA) or double-stranded DNA (dsDNA), the passage of DNA through the resulting break, and the rejoining of the broken phosphodiester backbone. DNA topoisomerase III from Escherichia coli belongs to the type IA family of DNA topoisomerases, which transiently cleave ssDNA via formation of a covalent 5' phosphotyrosine intermediate. Here we report the crystal structure, at 2.05 A resolution, of an inactive mutant of E. coli DNA topoisomerase III in a non-covalent complex with an 8-base ssDNA molecule. The enzyme undergoes a conformational change that allows the oligonucleotide to bind within a groove leading to the active site. We note that the ssDNA molecule adopts a conformation like that of B-DNA while bound to the enzyme. The position of the DNA within the realigned active site provides insight into the role of several highly conserved residues during catalysis. These findings confirm various aspects of the type IA topoisomerase mechanism while suggesting functional implications for other topoisomerases and proteins that perform DNA rearrangements.

PubMed: 11429611
DOI: 10.1038/35082615

実験手法

X-RAY DIFFRACTION (2.05 Å)