An Escherichia coli DNA topoisomerase I mutant has a compensatory mutation that alters two residues between functional domains of the DNA gyrase A protein.

نویسندگان

  • M Oram
  • L M Fisher
چکیده

Nucleotide sequence analysis revealed that the compensatory gyrA mutation in Escherichia coli DM750 affects DNA supercoiling by interchanging the identities of Ala-569 and Thr-586 in the DNA gyrase A subunit. These residues flank Arg-571, a site for trypsin cleavage that splits gyrase A protein between DNA breakage-reunion and DNA-binding domains. The putative interdomain locations of the DM750 mutation and that of E. coli DM800 (in gyrase B protein) suggests that these compensatory mutations may reduce DNA supercoiling activity by altering allosteric interactions in the gyrase complex.

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عنوان ژورنال:
  • Journal of bacteriology

دوره 174 12  شماره 

صفحات  -

تاریخ انتشار 1992