Crystal structure of the P2 C-repressor: a binder of nonpalindromic direct DNA repeats
2010 (English)In: Nucleic Acids Research, ISSN 0305-1048, E-ISSN 1362-4962, Vol. 38, no 21, 7778-7790 p.Article in journal (Refereed) Published
As opposed to the vast majority of prokaryoticrepressors, the immunity repressor of temperateEscherichia coli phage P2 (C) recognizes nonpalindromicdirect repeats of DNA rather thaninverted repeats. We have determined the crystalstructure of P2 C at 1.8A ° . This constitutes the firststructure solved from the family of C proteins fromP2-like bacteriophages. The structure reveals thatthe P2 C protein forms a symmetric dimer orientedto bind the major groove of two consecutive turns ofthe DNA. Surprisingly, P2 C has great similarities tobinders of palindromic sequences. Nevertheless, thetwo identical DNA-binding helixes of the symmetricP2 C dimer have to bind different DNA sequences.Helix 3 is identified as the DNA-recognition motif inP2 C by alanine scanning and the importance for theindividual residues in DNA recognition is defined.A truncation mutant shows that the disorderedC-terminus is dispensable for repressor function.The short distance between the DNA-bindinghelices together with a possible interaction betweentwo P2 C dimers are proposed to be responsible forextensive bending of the DNA. The structure providesinsight into the mechanisms behind the mutants ofP2 C causing dimer disruption, temperature sensitivityand insensitivity to the P4 antirepressor.
Place, publisher, year, edition, pages
2010. Vol. 38, no 21, 7778-7790 p.
DNA-binding protein, direct repeats, P2 C repressor
Research subject Structural Biology; Biochemistry
IdentifiersURN: urn:nbn:se:su:diva-42003DOI: 10.1093/nar/gkq626ISI: 000284952000042OAI: oai:DiVA.org:su-42003DiVA: diva2:343481
FunderThe Wenner-Gren FoundationSwedish Foundation for Strategic Research Swedish Research CouncilKnut and Alice Wallenberg Foundation