7T8K

BrxR from Acinetobacter BREX type I phage restriction system bound to DNA

7T8K の概要

• エントリーDOI: 10.2210/pdb7t8k/pdb
• 分子名称: BrxR, DNA, 1,2-ETHANEDIOL, ... (6 entities in total)
• 機能のキーワード: phage restriction, brex, dna binding, regulatory, acinetobacter, bacteriophage exclusion, dna binding protein, dna binding protein-dna complex, dna binding protein/dna
• 由来する生物種: Acinetobacter sp. NEB 394; 詳細
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 82593.95

構造登録者

Doyle, L.,Kaiser, B.,Stoddard, B. (登録日: 2021-12-16, 公開日: 2022-05-18, 最終更新日: 2024-04-03)

主引用文献

Luyten, Y.A.,Hausman, D.E.,Young, J.C.,Doyle, L.A.,Higashi, K.M.,Ubilla-Rodriguez, N.C.,Lambert, A.R.,Arroyo, C.S.,Forsberg, K.J.,Morgan, R.D.,Stoddard, B.L.,Kaiser, B.K.
Identification and characterization of the WYL BrxR protein and its gene as separable regulatory elements of a BREX phage restriction system.
Nucleic Acids Res., 50:5171-5190, 2022

PubMed Abstract: Bacteriophage exclusion ('BREX') phage restriction systems are found in a wide range of bacteria. Various BREX systems encode unique combinations of proteins that usually include a site-specific methyltransferase; none appear to contain a nuclease. Here we describe the identification and characterization of a Type I BREX system from Acinetobacter and the effect of deleting each BREX ORF on growth, methylation, and restriction. We identified a previously uncharacterized gene in the BREX operon that is dispensable for methylation but involved in restriction. Biochemical and crystallographic analyses of this factor, which we term BrxR ('BREX Regulator'), demonstrate that it forms a homodimer and specifically binds a DNA target site upstream of its transcription start site. Deletion of the BrxR gene causes cell toxicity, reduces restriction, and significantly increases the expression of BrxC. In contrast, the introduction of a premature stop codon into the BrxR gene, or a point mutation blocking its DNA binding ability, has little effect on restriction, implying that the BrxR coding sequence and BrxR protein play independent functional roles. We speculate that elements within the BrxR coding sequence are involved in cis regulation of anti-phage activity, while the BrxR protein itself plays an additional regulatory role, perhaps during horizontal transfer.

PubMed: 35511079
DOI: 10.1093/nar/gkac311

実験手法

X-RAY DIFFRACTION (2.3 Å)