title: Purification and properties of the Escherichia coli host factor required for inversion of the G segment in bacteriophage Mu.
abstract: G inversion in bacteriophage Mu requires the product of the DNA invertase gene gin and an Escherichia coli host factor termed FIS (factor for inversion stimulation). A recombination substrate must contain two recombination sites, arranged as inverted repeats, and a recombinational enhancer sequence termed sis. FIS has been purified to homogeneity. The purified protein has a relative molecular weight of 12,000 when analyzed under denaturing conditions. The intact protein behaves as a dimer of relative molecular weight 25,000 in gel filtration analysis. The purified protein does not possess any recombinogenic activity when assayed in the absence of the DNA-invertase Gin. In the presence of purified Gin FIS is the only additional protein required for efficient inversion. By performing gel retention assays, we show that FIS is a DNA-binding protein, which specifically binds to DNA fragments containing the recombinational enhancer sis.
mesh_terms: D002845:Chromatography; D007446:Chromosome Inversion; D003090:Coliphages / Q000235:genetics*; D004279:DNA, Viral / Q000378:metabolism*; D004926:Escherichia coli / Q000032:analysis*; D046911:Macromolecular Substances; D008970:Molecular Weight; D011995:Recombination, Genetic; D014764:Viral Proteins / Q000302:isolation & purification / Q000378:metabolism* / Q000494:pharmacology
chemical_list: D004279:DNA, Viral; D046911:Macromolecular Substances; D014764:Viral Proteins