title: Stable, monomeric variants of lambda Cro obtained by insertion of a designed beta-hairpin sequence.
abstract: lambda Cro is a dimeric DNA binding protein. Random mutagenesis and a selection for Cro activity have been used to identify the contacts between Cro subunits that are crucial for maintenance of a stably folded structure. To obtain equivalent contacts in a monomeric system, a Cro variant was designed and constructed in which the antiparallel beta-ribbon that forms the dimer interface was replaced by a beta-hairpin. The engineered monomer has a folded structure similar to wild type, is significantly more stable than wild type, and exhibits novel half-operator binding activity.
authors: Department of Biology, Massachusetts Institute of Technology, Cambridge 02139.
authors: M C
authors: MC
authors: Mossing
authors: R T
authors: RT
authors: Sauer
mesh_terms: D000595:Amino Acid Sequence; D010582:Bacteriophage lambda / Q000235:genetics*; D002942:Circular Dichroism; D004268:DNA-Binding Proteins; D004926:Escherichia coli / Q000235:genetics; D014644:Genetic Variation; D046911:Macromolecular Substances; D008958:Models, Molecular; D008969:Molecular Sequence Data; D016296:Mutagenesis; D011487:Protein Conformation; D012097:Repressor Proteins / Q000235:genetics* / Q000378:metabolism; D013816:Thermodynamics; D014157:Transcription Factors / Q000235:genetics*; D014764:Viral Proteins; D054334:Viral Regulatory and Accessory Proteins
chemical_list: D004268:DNA-Binding Proteins; D046911:Macromolecular Substances; D012097:Repressor Proteins; D014157:Transcription Factors; D014764:Viral Proteins; D054334:Viral Regulatory and Accessory Proteins; C016649:phage repressor proteins