Nucleic Acids Research, 1984, Vol. 12, No. 17 6779-6795
© 1984
MOLECULAR BIOLOGY |
Site-specificity of abnormal excision: the mechanism of formation of a specialized transducing bacteriophage
plac5*,
Shemyakin Institute of Bioorganic Chemistry, USSR Academy of Sciences ul. Vavilova 32, 117988 Moscow V-334, USSR
Received July 30, 1984. Accepted August 20, 1984.
Molecular mechanism of the specialized transducing bacteriophage
pZac5 formation has been studied. Phage-bacterial DNA junctions in
pZac5 DNA are localized and primary structure of regions of the abnormal excisional recombination leading to the phage formation is elucidated; the crossover region proved to be comparable with the central part of attP and attB sites (the core and the adjacent tetranucleotide) in length and degree of homology. Bacterial insert in
pZac5 DNA is shown to end immediately after Z-Y spacer, the DNA not containing ZacY gene segments. The data obtained led to the conclusion of site-specific (homologous) character of abnormal excision upon formation of lambda transducing bacteriophages. Possible mechanisms of the excision are discussed.
*Dedicated to the 15th anniversary of "Isolation of pure lac operon DNA" (1) as a token of admiration for the first genetic engineering study, which preceded the era of recombinant DNA in vitro and was performed without restriction endonucleases and molecular cloning. It is in that paper that
plac5 Phage was first described.
Preliminary note see (2). A part of the present work was reported at the All-Union Conference on Recombinant DNA (Pushchino, 1982).