8TWQ

Structure of bacteriophage lambda RexA protein

8TWQ の概要

• エントリーDOI: 10.2210/pdb8twq/pdb
• 分子名称: Protein rexA, SULFATE ION, CADMIUM ION, ... (4 entities in total)
• 機能のキーワード: phage, dna binding, dna binding protein
• 由来する生物種: Lambdavirus lambda
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 65042.66

構造登録者

Adams, M.C.,Chappie, J.S.,Schiltz, C.J. (登録日: 2023-08-21, 公開日: 2024-04-17, 最終更新日: 2024-11-13)

主引用文献

Adams, M.C.,Schiltz, C.J.,Sun, J.,Hosford, C.J.,Johnson, V.M.,Pan, H.,Borbat, P.P.,Freed, J.H.,Thomason, L.C.,Court, C.,Court, D.L.,Chappie, J.S.
The crystal structure of bacteriophage lambda RexA provides novel insights into the DNA binding properties of Rex-like phage exclusion proteins.
Nucleic Acids Res., 52:4659-4675, 2024

PubMed Abstract: RexA and RexB function as an exclusion system that prevents bacteriophage T4rII mutants from growing on Escherichia coli λ phage lysogens. Recent data established that RexA is a non-specific DNA binding protein that can act independently of RexB to bias the λ bistable switch toward the lytic state, preventing conversion back to lysogeny. The molecular interactions underlying these activities are unknown, owing in part to a dearth of structural information. Here, we present the 2.05-Å crystal structure of the λ RexA dimer, which reveals a two-domain architecture with unexpected structural homology to the recombination-associated protein RdgC. Modelling suggests that our structure adopts a closed conformation and would require significant domain rearrangements to facilitate DNA binding. Mutagenesis coupled with electromobility shift assays, limited proteolysis, and double electron-electron spin resonance spectroscopy support a DNA-dependent conformational change. In vivo phenotypes of RexA mutants suggest that DNA binding is not a strict requirement for phage exclusion but may directly contribute to modulation of the bistable switch. We further demonstrate that RexA homologs from other temperate phages also dimerize and bind DNA in vitro. Collectively, these findings advance our mechanistic understanding of Rex functions and provide new evolutionary insights into different aspects of phage biology.

PubMed: 38554102
DOI: 10.1093/nar/gkae212

実験手法

X-RAY DIFFRACTION (2.05 Å)