title: Mechanism of transposition of bacteriophage Mu: polarity of the strand transfer reaction at the initiation of transposition.
abstract: The distribution of newly synthesized DNA strands in the transposition products of bacteriophage Mu made in an in vitro system has been analyzed. The results support a model in which all Mu transpositions are initiated by a pair of strand transfer reactions that attach the 3' ends of Mu DNA to 5' protruding staggered ends of the target DNA. Joining of these ends produces a pair of structures similar to replication forks at the ends of the Mu DNA. Successful initiation of replication at either one or both ends, followed by a round of semiconservative replication, results in formation of a cointegrate structure. When the intermediate structure fails to replicate, breakage of the junctions between the Mu sequence and the vector sequence derived from the donor molecule can lead to a simple insert with a pair of gaps at the 5' ends of the Mu DNA. Evidence for a gap repair process that completes the simple insertion process has been obtained.
mesh_terms: D001483:Base Sequence; D003001:Cloning, Molecular; D003090:Coliphages / Q000235:genetics*; D004261:DNA Replication; D004262:DNA Restriction Enzymes; D004251:DNA Transposable Elements; D004279:DNA, Viral / Q000235:genetics* / Q000302:isolation & purification; D004926:Escherichia coli / Q000235:genetics*; D010957:Plasmids; D014779:Virus Replication
chemical_list: D004251:DNA Transposable Elements; D004279:DNA, Viral; D004262:DNA Restriction Enzymes