1ZVT

Structure of the E. coli ParC C-terminal domain

1ZVT の概要

• エントリーDOI: 10.2210/pdb1zvt/pdb
• 関連するPDBエントリー: 1ZVU
• 分子名称: Topoisomerase IV subunit A (2 entities in total)
• 機能のキーワード: beta-pinwheel, atpase, supercoiling, decatenation, dna binding, dna topology, isomerase
• 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: 55203.30

構造登録者

Corbett, K.D.,Schoeffler, A.J.,Thomsen, N.D.,Berger, J.M. (登録日: 2005-06-02, 公開日: 2005-07-05, 最終更新日: 2024-02-14)

主引用文献

Corbett, K.D.,Schoeffler, A.J.,Thomsen, N.D.,Berger, J.M.
The Structural Basis for Substrate Specificity in DNA Topoisomerase IV.
J.Mol.Biol., 351:545-561, 2005

PubMed Abstract: Most bacteria possess two type IIA topoisomerases, DNA gyrase and topo IV, that together help manage chromosome integrity and topology. Gyrase primarily introduces negative supercoils into DNA, an activity mediated by the C-terminal domain of its DNA binding subunit (GyrA). Although closely related to gyrase, topo IV preferentially decatenates DNA and relaxes positive supercoils. Here we report the structure of the full-length Escherichia coli ParC dimer at 3.0 A resolution. The N-terminal DNA binding region of ParC is highly similar to that of GyrA, but the ParC dimer adopts a markedly different conformation. The C-terminal domain (CTD) of ParC is revealed to be a degenerate form of the homologous GyrA CTD, and is anchored to the top of the N-terminal domains in a configuration different from that thought to occur in gyrase. Biochemical assays show that the ParC CTD controls the substrate specificity of topo IV, likely by capturing DNA segments of certain crossover geometries. This work delineates strong mechanistic parallels between topo IV and gyrase, while explaining how structural differences between the two enzyme families have led to distinct activity profiles. These findings in turn explain how the structures and functions of bacterial type IIA topoisomerases have evolved to meet specific needs of different bacterial families for the control of chromosome superstructure.

PubMed: 16023670
DOI: 10.1016/j.jmb.2005.06.029

実験手法

X-RAY DIFFRACTION (1.7 Å)