1rpe
From Proteopedia
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THE PHAGE 434 OR2/R1-69 COMPLEX AT 2.5 ANGSTROMS RESOLUTION
Overview
The crystal structure of the DNA-binding domain of bacteriophage 434, repressor (R1-69) in complex with a 20 base-pair DNA fragment has been, determined to 2.5 A resolution. The DNA fragment contains the sequence of, the OR2 operator site, which differs from the previously studied OR1 site, at three of the variable six central base-pairs. Comparison of the two, structures shows that the overall bent conformation of the DNA backbone as, well as the pattern of DNA-protein interactions seen in the OR1/R1-69, complex are maintained in the OR2 complex. However, the conformations of, the DNA base-pairs are different in the two structures. In particular, the, central base-pairs of OR2/R1-69 structure are more co-planar than in, OR1/R1-69, and there are no cross-strand "bifurcated" hydrogen bonds., These results show that binding of the protein causes operator DNA to, adopt a particular, well-defined backbone conformation, and they reinforce, the notion that the energetic cost of achieving this conformation, most, likely different for different sequences, can determine, at least in part, the relative affinity of the repressor for different operator sites.
About this Structure
1RPE is a Single protein structure of sequence from Bacteriophage 434. Full crystallographic information is available from OCA.
Reference
The phage 434 OR2/R1-69 complex at 2.5 A resolution., Shimon LJ, Harrison SC, J Mol Biol. 1993 Aug 5;232(3):826-38. PMID:8355273
Page seeded by OCA on Thu Nov 8 12:43:22 2007
