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Identification of a unique domain essential for Escherichia coli DNA topoisomerase III‐catalysed decatenation of replication intermediates
Author(s) -
Li Zhiyu,
Mondragón Alfonso,
Hiasa Hiroshi,
Marians Kenneth J.,
DiGate Russell J.
Publication year - 2000
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1046/j.1365-2958.2000.01763.x
Subject(s) - biology , topoisomerase , dna replication , escherichia coli , dna , replication factor c , plasmid , eukaryotic dna replication , dna supercoil , biochemistry , recombinant dna , microbiology and biotechnology , gene
A 17‐amino‐acid residue domain has been identified in Escherichia coli DNA topoisomerase III (Topo III) that is essential for Topo III‐mediated resolution of DNA replication intermediates in vitro . Deletion of this domain reduced Topo III‐catalysed resolution of DNA replication intermediates and decatenation of multiply linked plasmid DNA dimers by four orders of magnitude, whereas reducing Topo III‐catalysed relaxation of negatively supercoiled DNA substrates only 20‐fold. The presence of this domain has been detected in multiple plasmid‐encoded topoisomerases, raising the possibility that these enzymes may also be decatenases.