+検索条件
-Structure paper
タイトル | Structure, substrate binding and activity of a unique AAA+ protein: the BrxL phage restriction factor. |
---|---|
ジャーナル・号・ページ | Nucleic Acids Res, Vol. 51, Issue 8, Page 3513-3528, Year 2023 |
掲載日 | 2023年2月16日 |
著者 | Betty W Shen / Lindsey A Doyle / Rachel Werther / Abigail A Westburg / Daniel P Bies / Stephanie I Walter / Yvette A Luyten / Richard D Morgan / Barry L Stoddard / Brett K Kaiser / |
PubMed 要旨 | Bacteriophage exclusion ('BREX') systems are multi-protein complexes encoded by a variety of bacteria and archaea that restrict phage by an unknown mechanism. One BREX factor, termed BrxL, has been ...Bacteriophage exclusion ('BREX') systems are multi-protein complexes encoded by a variety of bacteria and archaea that restrict phage by an unknown mechanism. One BREX factor, termed BrxL, has been noted to display sequence similarity to various AAA+ protein factors including Lon protease. In this study we describe multiple CryoEM structures of BrxL that demonstrate it to be a chambered, ATP-dependent DNA binding protein. The largest BrxL assemblage corresponds to a dimer of heptamers in the absence of bound DNA, versus a dimer of hexamers when DNA is bound in its central pore. The protein displays DNA-dependent ATPase activity, and ATP binding promotes assembly of the complex on DNA. Point mutations within several regions of the protein-DNA complex alter one or more in vitro behaviors and activities, including ATPase activity and ATP-dependent association with DNA. However, only the disruption of the ATPase active site fully eliminates phage restriction, indicating that other mutations can still complement BrxL function within the context of an otherwise intact BREX system. BrxL displays significant structural homology to MCM subunits (the replicative helicase in archaea and eukaryotes), implying that it and other BREX factors may collaborate to disrupt initiation of phage DNA replication. |
リンク | Nucleic Acids Res / PubMed:36794719 / PubMed Central |
手法 | EM (単粒子) / X線回折 |
解像度 | 2.25 - 3.63 Å |
構造データ | EMDB-28244, PDB-8emc: EMDB-28248, PDB-8emh: PDB-8eil: |
化合物 | ChemComp-MLA: ChemComp-SIN: ChemComp-HOH: |
由来 |
|
キーワード | DNA BINDING PROTEIN (DNA結合タンパク質) / helicase (ヘリカーゼ) / phage restriction / LonP/RadA homolog / BREX / ANTIMICROBIAL PROTEIN (抗微生物ペプチド) / phage restriction factor / AAA+ protein. BrxL / AAA+ protein |