Mapping of a higher order protein-DNA complex: two kinds of long-range interactions in lambda attL.
To map the protein-protein and protein-DNA interactions involved in lambda site-specific recombination, Int cleavage assays with suicide substrates, nuclease protection patterns, gel retardation experiments, and quantitative Western blotting were applied to wild-type attL and attL mutants. The results lead to a model in which one IHF molecule bends the attL DNA and forms a higher order complex with the three bivalent Int molecules required for excisive recombination. It is proposed that each of the Int molecules binds in a unique manner: one bridges two DNA binding sites in cis, one is held via its high affinity amino-terminal DNA binding domain, and the third depends upon protein-protein interactions in addition to its low affinity carboxy-terminal DNA binding domain. This protein-DNA complex contains two unsatisfied DNA binding domains, each with a different sequence specificity, and is well suited to specific interactions with an appropriate recombination partner.
Kim
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Division of Biology and Medicine, Brown University, Providence, Rhode Island 02912.
Moitoso de Vargas
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Nunes-Düby
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SE
Landy
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A
D010582:Bacteriophage lambda / Q000235:genetics*; D001483:Base Sequence; D001665:Binding Sites; D004279:DNA, Viral / Q000235:genetics*; D004926:Escherichia coli / Q000235:genetics*; D008961:Models, Structural; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D010957:Plasmids; D011485:Protein Binding; D011995:Recombination, Genetic; D014764:Viral Proteins / Q000235:genetics*
D004279:DNA, Viral; D014764:Viral Proteins