8B1T

RecBCD-DNA in complex with the phage protein Abc2

Summary for 8B1T

• Entry DOI: 10.2210/pdb8b1t/pdb
• EMDB information: 15804 15805
• Descriptor: RecBCD enzyme subunit RecB, RecBCD enzyme subunit RecC, RecBCD enzyme subunit RecD, ... (7 entities in total)
• Functional Keywords: homologous recombination, dna repair, phage, helicase, nuclease, inhibitor, protein complex, enzyme, dna mimic, dna binding protein
• Biological source: Escherichia coli; More
• Total number of polymer chains: 5
• Total formula weight: 363642.51

Authors

Wilkinson, M.,Wilkinson, O.J.,Feyerherm, C.,Fletcher, E.E.,Wigley, D.B.,Dillingham, M.S. (deposition date: 2022-09-12, release date: 2022-12-28, Last modification date: 2024-07-24)

Primary citation

Wilkinson, M.,Wilkinson, O.J.,Feyerherm, C.,Fletcher, E.E.,Wigley, D.B.,Dillingham, M.S.
Structures of RecBCD in complex with phage-encoded inhibitor proteins reveal distinctive strategies for evasion of a bacterial immunity hub.
Elife, 11:-, 2022

PubMed Abstract: Following infection of bacterial cells, bacteriophage modulate double-stranded DNA break repair pathways to protect themselves from host immunity systems and prioritise their own recombinases. Here, we present biochemical and structural analysis of two phage proteins, gp5.9 and Abc2, which target the DNA break resection complex RecBCD. These exemplify two contrasting mechanisms for control of DNA break repair in which the RecBCD complex is either inhibited or co-opted for the benefit of the invading phage. Gp5.9 completely inhibits RecBCD by preventing it from binding to DNA. The RecBCD-gp5.9 structure shows that gp5.9 acts by substrate mimicry, binding predominantly to the RecB arm domain and competing sterically for the DNA binding site. Gp5.9 adopts a parallel coiled-coil architecture that is unprecedented for a natural DNA mimic protein. In contrast, binding of Abc2 does not substantially affect the biochemical activities of isolated RecBCD. The RecBCD-Abc2 structure shows that Abc2 binds to the Chi-recognition domains of the RecC subunit in a position that might enable it to mediate the loading of phage recombinases onto its single-stranded DNA products.

PubMed: 36533901
DOI: 10.7554/eLife.83409

Experimental method

ELECTRON MICROSCOPY (3.4 Å)