1XRX

Crystal structure of a DNA-binding protein

1XRX の概要

• エントリーDOI: 10.2210/pdb1xrx/pdb
• 関連するPDBエントリー: 1LRR
• 分子名称: SeqA protein, CALCIUM ION (3 entities in total)
• 機能のキーワード: protein filament, left-handed helix, dna replication inhibitor, replication inhibitor
• 由来する生物種: Escherichia coli
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 22820.81

構造登録者

Guarne, A.,Brendler, T.,Zhao, Q.,Ghirlando, R.,Austin, S.,Yang, W. (登録日: 2004-10-16, 公開日: 2005-05-10, 最終更新日: 2024-11-20)

主引用文献

Guarne, A.,Brendler, T.,Zhao, Q.,Ghirlando, R.,Austin, S.,Yang, W.
Crystal structure of a SeqA-N filament: implications for DNA replication and chromosome organization.
Embo J., 24:1502-1511, 2005

PubMed Abstract: Escherichia coli SeqA binds clusters of transiently hemimethylated GATC sequences and sequesters the origin of replication, oriC, from methylation and premature reinitiation. Besides oriC, SeqA binds and organizes newly synthesized DNA at replication forks. Binding to multiple GATC sites is crucial for the formation of stable SeqA-DNA complexes. Here we report the crystal structure of the oligomerization domain of SeqA (SeqA-N). The structural unit of SeqA-N is a dimer, which oligomerizes to form a filament. Mutations that disrupt filament formation lead to asynchronous DNA replication, but the resulting SeqA dimer can still bind two GATC sites separated from 5 to 34 base pairs. Truncation of the linker between the oligomerization and DNA-binding domains restricts SeqA to bind two GATC sites separated by one or two full turns. We propose a model of a SeqA filament interacting with multiple GATC sites that accounts for both origin sequestration and chromosome organization.

PubMed: 15933720
DOI: 10.1038/sj.emboj.7600634

実験手法

X-RAY DIFFRACTION (2.15 Å)