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Crystal structure of the BREX phage defence protein BrxA
- Source :
- Current Research in Structural Biology, Vol 4, Iss , Pp 211-219 (2022)
- Publication Year :
- 2022
- Publisher :
- Elsevier, 2022.
-
Abstract
- Bacteria are constantly challenged by bacteriophage (phage) infection and have developed multitudinous and varied resistance mechanisms. Bacteriophage Exclusion (BREX) systems protect from phage infection by generating methylation patterns at non-palindromic 6 bp sites in host bacterial DNA, to distinguish and block replication of non-self DNA. Type 1 BREX systems are comprised of six conserved core genes. Here, we present the first reported structure of a BREX core protein, BrxA from the phage defence island of Escherichia fergusonii ATCC 35469 plasmid pEFER, solved to 2.09 Å. BrxA is a monomeric protein in solution, with an all α-helical globular fold. Conservation of surface charges and structural homology modelling against known phage defence systems highlighted that BrxA contains two helix-turn-helix motifs, juxtaposed by 180°, positioned to bind opposite sides of a DNA major groove. BrxA was subsequently shown to bind dsDNA. This new understanding of BrxA structure, and first indication of BrxA biological activity, suggests a conserved mode of DNA-recognition has become widespread and implemented by diverse phage defence systems.
- Subjects :
- Biology (General)
QH301-705.5
Subjects
Details
- Language :
- English
- ISSN :
- 2665928X
- Volume :
- 4
- Issue :
- 211-219
- Database :
- Directory of Open Access Journals
- Journal :
- Current Research in Structural Biology
- Publication Type :
- Academic Journal
- Accession number :
- edsdoj.6788e7788eb84c889b59786e70d0b39a
- Document Type :
- article
- Full Text :
- https://doi.org/10.1016/j.crstbi.2022.06.001