8C45

PglX methyltransferase from the Salmonella BREX phage defence system (aka BrxX)

8C45 の概要

• エントリーDOI: 10.2210/pdb8c45/pdb
• 分子名称: site-specific DNA-methyltransferase (adenine-specific), S-ADENOSYLMETHIONINE (2 entities in total)
• 機能のキーワード: phage defence, dna binding protein
• 由来する生物種: Salmonella enterica subsp. enterica serovar Typhimurium str. D23580
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 283811.59

構造登録者

Blower, T.R.,Went, S.C. (登録日: 2023-01-01, 公開日: 2024-07-10, 最終更新日: 2024-09-04)

主引用文献

Went, S.C.,Picton, D.M.,Morgan, R.D.,Nelson, A.,Brady, A.,Mariano, G.,Dryden, D.T.F.,Smith, D.L.,Wenner, N.,Hinton, J.C.D.,Blower, T.R.
Structure and rational engineering of the PglX methyltransferase and specificity factor for BREX phage defence.
Nat Commun, 15:7236-7236, 2024

PubMed Abstract: Bacteria have evolved a broad range of systems that provide defence against their viral predators, bacteriophages. Bacteriophage Exclusion (BREX) systems recognise and methylate 6 bp non-palindromic motifs within the host genome, and prevent replication of non-methylated phage DNA that encodes these same motifs. How BREX recognises cognate motifs has not been fully understood. In this study we characterise BREX from pathogenic Salmonella and present X-ray crystallographic structures of the conserved BREX protein, PglX. The PglX N-terminal domain encodes the methyltransferase, whereas the C-terminal domain is for motif recognition. We also present the structure of PglX bound to the phage-derived DNA mimic, Ocr, an inhibitor of BREX activity. Our analyses propose modes for DNA-binding by PglX and indicate that both methyltransferase activity and defence require larger BREX complexes. Through rational engineering of PglX we broaden both the range of phages targeted, and the host motif sequences that are methylated by BREX. Our data demonstrate that PglX is used to recognise specific DNA sequences for BREX activity, contributing to motif recognition for both phage defence and host methylation.

PubMed: 39174540
DOI: 10.1038/s41467-024-51629-7

実験手法

X-RAY DIFFRACTION (3.5 Å)