Nucleic Acids Research, 1988, Vol. 16, No. 21 10199-10212
© 1988
MOLECULAR BIOLOGY |
Structural bases of a long-stretched deletion: completing the
plac5 DNA primary structure
Institute of Bioorganic Chemistry, Byelorussian Academy of Sciences Minsk 220023, USSR 1Shemyakin Institute of Bioorganic Chemistry, USSR Academy of Sciences Mascow 117811, USSR
Received July 8, 1988. Accepted October 8, 1988.
In studying molecular mechanisms of specialised transduction. the lac1 (E. coli)-Ea47(
) DNA junction in transducing bacteriophage
plac5 has been structural1y elucidated, thus yielding the complete sequence of
plac5 DNA including the lac5 substitution, a well-known segment of lambdoid vectors. The
phac5 DNA is shown to consist of 19368 bp (
left arm) + 3924 bp
plac5 substitution)+25353 bp (
right arm), totally amounting to 48645 bp. The presence of the phage pbL promoter near to the right end of the lac5 insert is shown. The lacl gene distal end in
plac5 proved to be much longer than it was oostulated earlier. codinq for 224 C-terminal amino acid residues of lac repressor. Both the recombination studied in this paper and the earlier studied abnormal prophage excision (2,3) occur near to Chi-like structures (chi*Lac1 and chi*lom, respectively). On thebasis of the data obtained, a key role of the E. coli RecBCD system and Chi-like sequences in the formation of deletions in bacterial cells is suggested.
Part of this work was published in a Letter to the Editor (1).