Interaction of proteins located at a distance along DNA: mechanism of target immunity in the Mu DNA strand-transfer reaction.
DNA molecules carrying a Mu end(s) are inefficient targets in the Mu DNA strand-transfer reaction. This target immunity is due to preferential dissociation of Mu B protein from DNA molecules that have Mu A protein bound to the Mu end; free DNA is a much poorer target than DNA with Mu B protein bound. We show that Mu B protein, which binds nonspecifically to DNA, is immobile once bound. An encounter between Mu A and Mu B proteins, bound some distance apart along DNA, is necessary to facilitate the Mu B dissociation. Experiments which show that DNA without a Mu end can acquire immunity, by catenation to DNA with a Mu end(s), are consistent with a model of Mu A-Mu B interaction by DNA looping, but not by linear movement of protein(s) along DNA.
Adzuma
K
K
Laboratory of Molecular Biology, National Institutes of Health, Bethesda, Maryland 20892.
Mizuuchi
K
K
D002874:Chromosome Mapping; D004251:DNA Transposable Elements; D004269:DNA, Bacterial / Q000235:genetics* / Q000502:physiology; D004268:DNA-Binding Proteins / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics*; D007109:Immunity; D009713:Nucleotidyltransferases / Q000378:metabolism*; D019895:Transposases; D014764:Viral Proteins
D004251:DNA Transposable Elements; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins; C050938:Mu B protein, bacteriophage; D014764:Viral Proteins; D009713:Nucleotidyltransferases; D019895:Transposases