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Sequence rearrangements may alter the in vivo superhelicity of recombinant plasmids
Author(s) -
Amster O.,
Zamir A.
Publication year - 1986
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(86)80305-2
Subject(s) - plasmid , pbr322 , biology , recombinant dna , transposable element , genetics , bamhi , microbiology and biotechnology , dna , complementary dna , restriction map , gene , genome
Electrophoretic resolution of topoisomers was used to compare the in vivo superhelicity of recombinant plasmids containing a fragment of cDNA for an immunoglobulin light chain, cloned in the two possible orientations into the Bam HI site of pBR313 or pBR322. Previously, frequent transpositions of IS1 or IS5 were observed into the sequence upstream to the cloned fragment in recombinants in one orientation [(+) plasmids] but not in recombinants in the opposite, (−) orientation [(1982) Nucleic Acids Res. 10, 4525‐4542]. The results of the present analyses show that, on average, (−) plasmids are less negatively supercoiled than (+) plasmids, or pBR322. These results suggest that primary sequence rearrangements in plasmids could affect their in vivo topological state, and consequently, perhaps, their effectiveness as recipients of transposable elements.