4cro

Publication Abstract from PubMed

The structure of a complex of bacteriophage lambda Cro protein with a 17-base-pair operator has been determined at 3.9-A resolution. Isomorphous derivatives obtained by the synthesis of site-specific iodinated DNA oligomers were of critical importance in solving the structure. The crystal structure contains three independent Cro-operator complexes that have very similar, although not necessarily identical, conformations. In the complex, the protein dimer undergoes a large conformational change relative to the crystal structure of the free protein. One monomer rotates by about 40 degrees relative to the other, this being accomplished primarily by a twisting of the two beta-sheet strands that connect one monomer with the other. In the complex, the DNA is bent by about 40 degrees into the shape of a boomerang but maintains essentially Watson-Crick B-form. In contrast to other known protein-DNA complexes, the DNA is not stacked end-to-end. The structure confirms the general features of the model previously proposed for the interaction of Cro with DNA.

Protein-DNA conformational changes in the crystal structure of a lambda Cro-operator complex.,Brennan RG, Roderick SL, Takeda Y, Matthews BW Proc Natl Acad Sci U S A. 1990 Oct;87(20):8165-9. PMID:2146682^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.