High-resolution structure of an engineered Cro monomer shows changes in conformation relative to the native dimer.
Albright, R.A., Mossing, M.C., Matthews, B.W.(1996) Biochemistry 35: 735-742
- PubMed: 8547253 
- DOI: https://doi.org/10.1021/bi951958n
- Primary Citation of Related Structures:  
1ORC - PubMed Abstract: 
A rationally designed, genetically engineered, monomeric form of the Cro protein from bacteriophage lambda has been crystallized and its structure determined by isomorphous replacement and refined to a resolution of 1.54 A. The structure confirms the rationale of the design but, at the same time, reveals 1-2 A shifts throughout the monomer structure relative to the previously determined structure of the dimeric wild-type protein. These changes include a 1.6 A main-chain shift in part of the beta-sheet region of the molecule relative to the alpha-helical region and a 1.1 A shift of a buried phenylalanine within the core as well as a correlated 2.2 A shift in a solvent-exposed beta-hairpin. The conformational adjustments appear to reflect an inherent flexibility of the protein that is associated with its DNA-binding function.
Organizational Affiliation: 
Institute of Molecular Biology, Howard Hughes Medical Institute, University of Oregon, Eugene 97403, USA.