Direct evidence for the formation of precatenanes during DNA replication
| Autor: | Alicia Castán, Víctor Antonio Vidal Martínez, Dora B. Krimer, Jorge Cebrián, Pablo E. Hernández, Cristina Parra, Christian E. Schaerer, María José Fernández-Nestosa, Jorge Bernardo Schvartzman, Maridian J. Kadomatsu-Hermosa |
|---|---|
| Přispěvatelé: | Ministerio de Economía y Competitividad (España) |
| Rok vydání: | 2015 |
| Předmět: |
DNA Replication
DNA Topoisomerase IV DNA Bacterial Bacterial plasmids DNA and Chromosomes Biochemistry Catalysis Minichromosome maintenance Control of chromosome duplication Escherichia coli Agarose-gel electrophoresis skin and connective tissue diseases Molecular Biology Genetics Electrophoresis Agar Gel biology DNA Superhelical Topoisomerase Circular bacterial chromosome DNA replication Nucleic Acid Hybridization Cell Biology Cell biology Culture Media Prokaryotic DNA replication Drug Design biology.protein DNA supercoil Replisome Nucleic Acid Conformation sense organs Plasmids |
| Zdroj: | Digital.CSIC. Repositorio Institucional del CSIC instname |
| Popis: | 11 págs.; 9 figs. este artículo forma parte de tesis doctoral https://digital.csic.es/handle/10261/120925 The dynamics of DNA topology during replication are still poorly understood. Bacterial plasmids are negatively supercoiled. This underwinding facilitates strand separation of the DNA duplex during replication. Leading the replisome, a DNA helicase separates the parental strands that are to be used as templates. This strand separation causes overwinding of the duplex ahead. If this overwinding persists, it would eventually impede fork progression. In bacteria, DNA gyrase and topoisomerase IV act ahead of the fork to keep DNA underwound. However, the processivity of the DNA helicase might overcome DNA gyrase and topoisomerase IV. It was proposed that the overwinding that builds up ahead of the fork could force it to swivel and diffuse this positive supercoiling behind the fork where topoisomerase IV would also act to maintain replicating the DNA underwound. Putative intertwining of sister duplexes in the replicated region are called precatenanes. Fork swiveling and the formation of precatenanes, however, are still questioned. Here, we used classical genetics and high resolution two-dimensional agarose gel electrophoresis to examine the torsional tension of replication intermediates of three bacterial plasmids with the fork stalled at different sites before termination. The results obtained indicated that precatenanes do form as replication progresses before termination. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc. This work was supported by Grant BFU2011-22489 from the Spanish Ministerio de Economía y Competitividad and European FEDER Funds (to J. B. S.). |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|