| Abstract: |
Proper geometric and topological organization of DNA is essential for all chromosomal processes. Two classes of proteins play major roles in organizing chromosomes: Condensin complexes and type II topoisomerases. In Escherichia coli, MukB, a structural maintenance of chromosome-like component of the bacterial condensin, and topoisomerase IV (Topo IV), a type II topoisomerase that decatenates the newly replicated daughter chromosomes, are both essential for chromosome segregation in rapidly growing cells. However, little is known about the interplay between MukB and Topo IV. Here we demonstrate a physical and functional interaction between MukB and ParC, a subunit of Topo IV, in vitro. The site of MukB interaction was located on the C-terminal domain of ParC and a loss-of-interaction mutant, ParC R705E R729A, was isolated. This variant retained full activity as a topoisomerase when reconstituted with ParE to form Topo IV. We show that MukB stimulates the superhelical DNA relaxation activity of wild-type Topo IV, but not that of Topo IV reconstituted with ParC R705E R729A. |
| Keywords: |
controlled study; unclassified drug; dna-binding proteins; mutation, missense; nonhuman; conference paper; dna replication; protein localization; chromosomal proteins, non-histone; amino acid substitution; carboxy terminal sequence; protein protein interaction; enzyme activity; wild type; escherichia coli; protein structure, tertiary; multiprotein complexes; condensin; bacterial dna; adenosine triphosphatases; dna, bacterial; dna topoisomerase iv; protein parc; chromosomes, bacterial; escherichia coli proteins; gene activity; protein isolation; bacterial gene; bacterium mutant; dna, superhelical; bacterial enzyme; decatenase topoisomerase iv; mukb protein; protein pare; enzyme reconstitution
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