Purification and crystallization of CII: an unstable transcription activator from phage lambda.
The CII protein of the temperate bacteriophage lambda is a transcriptional activator involved in the lysis-lysogeny switch of the phage. It is an unstable protein of 97 amino acids and is known to exist as a tetramer in the native state. The cII gene has been cloned and expressed in Escherichia coli using a T7 promoter based over-expression system. The recombinant CII protein has been purified to homogeneity by ammonium sulfate fractionation followed by two steps of ion-exchange chromatography. The purified protein crystallized at pH 8.2 in hanging-drop vapor diffusion method at 293 K. The crystals diffract to a resolution of 2.8 A and belong to the space group C222 with unit-cell parameters a = 64.10, b = 106.95 and c = 120.16 A.
Datta
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Department of Biochemistry, Bose Institute, P-1/12 CIT Scheme VIIM, Kolkata, 700054, India.
Chakrabarti
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Subramanya
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Parrack
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D010582:Bacteriophage lambda / Q000737:chemistry* / Q000235:genetics; D003460:Crystallization; D004591:Electrophoresis, Polyacrylamide Gel; D013816:Thermodynamics; D014157:Transcription Factors / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification*; D014764:Viral Proteins; D014961:X-Ray Diffraction / Q000379:methods
D014157:Transcription Factors; D014764:Viral Proteins; C039000:cII protein, bacteriophage lambda