A role for topoisomerase III in Escherichia coli chromosome segregation.

ABSTRACT: The cellular function of Escherichia coli topoisomerase III remains elusive. We show that rescue of temperature-sensitive mutants in parE and parC (encoding the subunits of the chromosomal decatenase topoisomerase IV) at restrictive temperatures by high-copy suppressors is strictly dependent on topB (encoding topoisomerase III). Double mutants of parEΔtopB and parCΔtopB were barely viable, grew slowly, and were defective in chromosome segregation at permissive temperatures. The topB mutant phenotype did not result from accumulation of toxic recombination intermediates, because it was not relieved by mutations in either recQ or recA. In addition, in an otherwise wild-type genetic background, ΔtopB cells treated with the type II topoisomerase inhibitor novobiocin displayed aberrant chromosom

SUBMITTER: Perez-Cheeks BA 

PROVIDER: S-EPMC3549057 | biostudies-literature | 2012 Nov

REPOSITORIES: biostudies-literature