8GMU

Structure of lambda repressor in complex with RecA filament

Summary for 8GMU

• Entry DOI: 10.2210/pdb8gmu/pdb
• EMDB information: 34154
• Descriptor: Repressor protein cI, Protein RecA, DNA (5'-D(P*TP*TP*TP*TP*TP*T)-3'), ... (5 entities in total)
• Functional Keywords: sos response, reca, lambda repressor, filament, dna repair, helical reconstruction, dna binding protein-dna complex, dna binding protein/dna
• Biological source: Escherichia phage Lambda; More
• Total number of polymer chains: 4
• Total formula weight: 93907.69

Authors

Gao, B.,Feng, Y. (deposition date: 2022-08-22, release date: 2022-12-21, Last modification date: 2024-07-03)

Primary citation

Gao, B.,Liang, L.,Su, L.,Wen, A.,Zhou, C.,Feng, Y.
Structural basis for regulation of SOS response in bacteria.
Proc.Natl.Acad.Sci.USA, 120:e2217493120-e2217493120, 2023

PubMed Abstract: In response to DNA damage, bacterial RecA protein forms filaments with the assistance of DinI protein. The RecA filaments stimulate the autocleavage of LexA, the repressor of more than 50 SOS genes, and activate the SOS response. During the late phase of SOS response, the RecA filaments stimulate the autocleavage of UmuD and λ repressor CI, leading to mutagenic repair and lytic cycle, respectively. Here, we determined the cryo-electron microscopy structures of RecA filaments in complex with DinI, LexA, UmuD, and λCI by helical reconstruction. The structures reveal that LexA and UmuD dimers bind in the filament groove and cleave in an intramolecular and an intermolecular manner, respectively, while λCI binds deeply in the filament groove as a monomer. Despite their distinct folds and oligomeric states, all RecA filament binders recognize the same conserved protein features in the filament groove. The SOS response in bacteria can lead to mutagenesis and antimicrobial resistance, and our study paves the way for rational drug design targeting the bacterial SOS response.

PubMed: 36598938
DOI: 10.1073/pnas.2217493120

Experimental method

ELECTRON MICROSCOPY (2.78 Å)