title: Purification and self-association equilibria of the lysis-lysogeny switch proteins of coliphage 186.
abstract: The CI repressor protein, responsible for maintenance of the lysogenic state, and the Apl protein, required for efficient prophage induction, are the two control proteins of the lysis-lysogeny transcriptional switch of coliphage 186.  These proteins have been overexpressed, purified, and their self-association behavior examined by sedimentation equilibrium.  Phage 186 CI dimers self-associate in solution through tetramers to octamers in a concerted process.  The Apl protein of 186 is an unusual example of a helix-turn-helix protein which is monomeric in solution.
authors.affiliation: Department of Biochemistry, University of Adelaide, Australia.
authors.forename: K E
authors.initials: KE
authors.lastname: Shearwin
authors.forename: J B
authors.initials: JB
authors.lastname: Egan
mesh_terms: D001483:Base Sequence; D001665:Binding Sites; D002846:Chromatography, Affinity; D002850:Chromatography, Gel; D003001:Cloning, Molecular; D003090:Coliphages / Q000502:physiology*; D004247:DNA / Q000378:metabolism; D017931:DNA Primers; D004268:DNA-Binding Proteins; D004926:Escherichia coli; D019077:Helix-Turn-Helix Motifs; D007700:Kinetics; D008242:Lysogeny; D046911:Macromolecular Substances; D008961:Models, Structural; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D012097:Repressor Proteins / Q000096:biosynthesis / Q000302:isolation & purification* / Q000378:metabolism*; D013816:Thermodynamics; D014158:Transcription, Genetic; D014461:Ultracentrifugation; D014764:Viral Proteins; D054334:Viral Regulatory and Accessory Proteins
chemical_list: D017931:DNA Primers; D004268:DNA-Binding Proteins; D046911:Macromolecular Substances; D012097:Repressor Proteins; D014764:Viral Proteins; D054334:Viral Regulatory and Accessory Proteins; C016649:phage repressor proteins; D004247:DNA