Topoisomerase IV can functionally replace all type 1A topoisomerases in Bacillus subtilis
| Autor: | Daniel R. Reuß, Philipp Joel Mroch, Anja Pöhlein, Inam Ul-Haq, Patrick Faßhauer, Byoung-Mo Koo, Sabine Brantl, Rolf Daniel, Jörg Stülke, Carol A. Gross |
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| Rok vydání: | 2019 |
| Předmět: |
DNA Replication
DNA Topoisomerase IV DNA Bacterial Topoisomerase IV Mutant Bacillus subtilis Biology 03 medical and health sciences chemistry.chemical_compound 0302 clinical medicine Bacterial Proteins Escherichia coli Genetics Point Mutation Promoter Regions Genetic Molecular Biology Gene 030304 developmental biology 0303 health sciences DNA Superhelical Escherichia coli Proteins Topoisomerase Point mutation DNA-Directed RNA Polymerases Chromosomes Bacterial biology.organism_classification topoisomerase Phenotype DNA Topoisomerases Type I chemistry Mutation biology.protein DNA supercoil Genome Bacterial 030217 neurology & neurosurgery DNA |
| Zdroj: | Nucleic Acids Research |
| ISSN: | 1362-4962 0305-1048 |
| DOI: | 10.1093/nar/gkz260 |
| Popis: | DNA topoisomerases play essential roles in chromosome organization and replication. Most bacteria possess multiple topoisomerases which have specialized functions in the control of DNA supercoiling or in DNA catenation/decatenation during recombination and chromosome segregation. DNA topoisomerase I is required for the relaxation of negatively supercoiled DNA behind the transcribing RNA polymerase. Conflicting results have been reported on the essentiality of the topA gene encoding topoisomerase I in the model bacterium Bacillus subtilis. In this work, we have studied the requirement for topoisomerase I in B. subtilis. All stable topA mutants carried different chromosomal amplifications of the genomic region encompassing the parEC operon encoding topoisomerase IV. Using a fluorescent amplification reporter system we observed that each individual topA mutant had acquired such an amplification. Eventually, the amplifications were replaced by a point mutation in the parEC promoter region which resulted in a fivefold increase of parEC expression. In this strain both type I topoisomerases, encoded by topA and topB, were dispensable. Our results demonstrate that topoisomerase IV at increased expression is necessary and sufficient to take over the function of type 1A topoisomerases. peerReviewed |
| Databáze: | OpenAIRE |
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