3JSO

Classic Protein With a New Twist: crystal structure of a LexA repressor DNA complex

Summary for 3JSO

• Entry DOI: 10.2210/pdb3jso/pdb
• Related: 3JSP
• Descriptor: LexA repressor, DNA (5'-D(*TP*AP*TP*AP*CP*TP*GP*TP*AP*TP*AP*TP*AP*TP*AP*TP*AP*CP*AP*GP*TP*A)-3') (3 entities in total)
• Functional Keywords: protein-dna complex, winged helix-turn-helix, double helix, repressor, lexa, sos system, autocatalytic cleavage, dna damage, dna repair, dna replication, dna-binding, hydrolase, sos response, transcription, transcription regulation, hydrolase-dna complex, hydrolase/dna
• Biological source: Escherichia coli K-12
• Total number of polymer chains: 4
• Total formula weight: 58158.05

Authors

Zhang, A.P.P.,Pigli, Y.Z.,Rice, P.A. (deposition date: 2009-09-10, release date: 2010-08-18, Last modification date: 2024-02-21)

Primary citation

Zhang, A.P.,Pigli, Y.Z.,Rice, P.A.
Structure of the LexA-DNA complex and implications for SOS box measurement.
Nature, 466:883-886, 2010

PubMed Abstract: The eubacterial SOS system is a paradigm of cellular DNA damage and repair, and its activation can contribute to antibiotic resistance. Under normal conditions, LexA represses the transcription of many DNA repair proteins by binding to SOS 'boxes' in their operators. Under genotoxic stress, accumulating complexes of RecA, ATP and single-stranded DNA (ssDNA) activate LexA for autocleavage. To address how LexA recognizes its binding sites, we determined three crystal structures of Escherichia coli LexA in complex with SOS boxes. Here we report the structure of these LexA-DNA complexes. The DNA-binding domains of the LexA dimer interact with the DNA in the classical fashion of a winged helix-turn-helix motif. However, the wings of these two DNA-binding domains bind to the same minor groove of the DNA. These wing-wing contacts may explain why the spacing between the two half-sites of E. coli SOS boxes is invariant.

PubMed: 20703307
DOI: 10.1038/nature09200

Experimental method

X-RAY DIFFRACTION (2.29 Å)