Division of labor among monomers within the Mu transposase tetramer.
A single tetramer of Mu transposase (MuA) pairs the recombination sites, cleaves the donor DNA, and joins these ends to a target DNA by strand transfer. Analysis of C-terminal deletion derivatives of MuA reveals that a 30 amino acid region between residues 575 and 605 is critical for these three steps. Although inactive on its own, a deletion protein lacking this region assembles with the wild-type protein. These mixed tetramers carry out donor cleavage but do not promote strand transfer, even when the donor cleavage stage is bypassed. These data suggest that the active center of the transposase is composed of the C-terminus of four MuA monomers; one dimer carries out donor cleavage while all four monomers contribute to strand transfer.
Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases National Institutes of Health, Bethesda, Maryland 20892.
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Baker
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Mizuuchi
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Savilahti
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Mizuuchi
D010584:Bacteriophage phi X 174 / Q000378:metabolism*; D004277:DNA, Single-Stranded / Q000378:metabolism; D004279:DNA, Viral / Q000378:metabolism; D007700:Kinetics; D046911:Macromolecular Substances; D008961:Models, Structural; D009713:Nucleotidyltransferases / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism*; D010957:Plasmids; D011994:Recombinant Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D017384:Sequence Deletion; D019895:Transposases
D004277:DNA, Single-Stranded; D004279:DNA, Viral; D046911:Macromolecular Substances; D011994:Recombinant Proteins; D009713:Nucleotidyltransferases; D019895:Transposases