Target immunity of Mu transposition reflects a differential distribution of Mu B protein.
A DNA molecule carrying Mu end DNA sequence(s) is a poor target in the Mu DNA strand-transfer reaction, a phenomenon which is referred to as "target immunity." We find that Mu B protein stimulates intermolecular strand-transfer by binding to the target DNA. Our results show that a differential distribution of Mu B protein between "immune" and "non-immune" DNA molecules is responsible for target immunity; in the presence of Mu A protein and ATP, Mu B protein dissociates preferentially from immune DNA molecules. Hydrolysis of ATP is implicated in establishing the differential distribution of Mu B protein between immune and non-immune DNA molecules in the presence of Mu A protein; nonhydrolyzable ATP gamma S can support an efficient strand-transfer reaction even with a target DNA that is immune in a reaction with ATP.
Adzuma
K
K
Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, Maryland 20892.
Mizuuchi
K
K
D000251:Adenosine Triphosphatases / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism; D003090:Coliphages / Q000201:enzymology / Q000235:genetics*; D004279:DNA, Viral / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics*; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics*; D005796:Genes; D005814:Genes, Viral; D011995:Recombination, Genetic
D004279:DNA, Viral; D004268:DNA-Binding Proteins; D000255:Adenosine Triphosphate; D000251:Adenosine Triphosphatases