title: Anomalous behavior of bacteriophage lambda polypeptides in polyacrylamide gels: resolution, identification, and control of the lambda rex gene product.
abstract: The resolution of lambia proteins was compared on the two types of sodium dodecyl sulfate-polyacrylamide gels commonly in use. The two kinds of gel differ essentially in the ratio of the cross-linker, N'-N-bismethylene-acrylamide (bisacrylamide), to acrylamide monomer. Several lambda proteins migrate relatively more slowly in gels with high bisacrylamide/acrylamide ratios (HB gels) than in gels with low ratios, although the two types of gel are of roughly equivalent porosity. This effect is illustrated by a change in relative position of both the Rex and Int proteins, with apparent increases in molecular weight of about 8 and 15%, respectively, in the HB gels. This work confirms that like repressor and Int, the 28.5-kilodalton protein, identified as Rex on HB gels, is postively regulated by the lambdacII and cIII products and negatively controlled Cro. An intact y site is required for Rex and repressor expression after infection, whereas their synthesis in a lysogen is dependent upon a functional maintenance promoter, Prm.
mesh_terms: D003090:Coliphages / Q000032:analysis* / Q000235:genetics; D004591:Electrophoresis, Polyacrylamide Gel / Q000379:methods*; D005809:Genes, Regulator; D005814:Genes, Viral; D008242:Lysogeny; D009154:Mutation; D010455:Peptides / Q000032:analysis*; D014764:Viral Proteins / Q000032:analysis* / Q000235:genetics
chemical_list: D010455:Peptides; D014764:Viral Proteins