2XCJ
Crystal structure of P2 C, the immunity repressor of temperate E. coli phage P2
Summary for 2XCJ
| Entry DOI | 10.2210/pdb2xcj/pdb |
| Descriptor | C PROTEIN, SODIUM ION, GLYCEROL, ... (5 entities in total) |
| Functional Keywords | direct repeats, repressor, helix-turn-helix, viral protein |
| Biological source | ENTEROBACTERIA PHAGE P2 |
| Total number of polymer chains | 2 |
| Total formula weight | 22328.99 |
| Authors | Massad, T.,Skaar, K.,Hogbom, M.,Stenmark, P. (deposition date: 2010-04-23, release date: 2010-07-28, Last modification date: 2024-05-08) |
| Primary citation | Massad, T.,Skaar, K.,Nilsson, H.,Damberg, P.,Henriksson-Peltola, P.,Haggard-Ljungquist, E.,Hogbom, M.,Stenmark, P. Crystal Structure of the P2 C-Repressor: A Binder of Non-Palindromic Direct DNA Repeats. Nucleic Acids Res., 38:7778-, 2010 Cited by PubMed Abstract: As opposed to the vast majority of prokaryotic repressors, the immunity repressor of temperate Escherichia coli phage P2 (C) recognizes non-palindromic direct repeats of DNA rather than inverted repeats. We have determined the crystal structure of P2 C at 1.8 Å. This constitutes the first structure solved from the family of C proteins from P2-like bacteriophages. The structure reveals that the P2 C protein forms a symmetric dimer oriented to bind the major groove of two consecutive turns of the DNA. Surprisingly, P2 C has great similarities to binders of palindromic sequences. Nevertheless, the two identical DNA-binding helixes of the symmetric P2 C dimer have to bind different DNA sequences. Helix 3 is identified as the DNA-recognition motif in P2 C by alanine scanning and the importance for the individual residues in DNA recognition is defined. A truncation mutant shows that the disordered C-terminus is dispensable for repressor function. The short distance between the DNA-binding helices together with a possible interaction between two P2 C dimers are proposed to be responsible for extensive bending of the DNA. The structure provides insight into the mechanisms behind the mutants of P2 C causing dimer disruption, temperature sensitivity and insensitivity to the P4 antirepressor. PubMed: 20639540DOI: 10.1093/NAR/GKQ626 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (1.8 Å) |
Structure validation
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