The Three Chemical Steps of Tn10/IS10 Transposition Involve Repeated Utilization of a Single Active Site

摘要: Abstract Nonreplicative transposition by Tn10/IS10 involves three chemical steps at each transposon end: cleavage of the two strands plus joining one strand to target DNA. These occur within a synaptic complex comprising ends and monomers IS10 transposase. We report four transposase mutations that individually abolish without affecting complex. conclude single constellation residues, "active site," directly catalyzes steps. Analyses reactions containing mixtures wild-type catalysis-defective transposases indicate monomer end transfer is carried out same previously catalyzed cleavage. other data suggest active site unit carries all in succession end.