Evaluation of Biological and Physical Protection against Nuclease Degradation of Clay-Bound Plasmid DNA
AUTOR(ES)
Demanèche, Sandrine
FONTE
American Society for Microbiology
RESUMO
In order to determine the mechanisms involved in the persistence of extracellular DNA in soils and to monitor whether bacterial transformation could occur in such an environment, we developed artificial models composed of plasmid DNA adsorbed on clay particles. We determined that clay-bound DNA submitted to an increasing range of nuclease concentrations was physically protected. The protection mechanism was mainly related to the adsorption of the nuclease on the clay mineral. The biological potential of the resulting DNA was monitored by transforming the naturally competent proteobacterium Acinetobacter sp. strain BD413, allowing us to demonstrate that adsorbed DNA was only partially available for transformation. This part of the clay-bound DNA which was available for bacteria, was also accessible to nucleases, while the remaining fraction escaped both transformation and degradation. Finally, transformation efficiency was related to the perpetuation mechanism, with homologous recombination being less sensitive to nucleases than autonomous replication, which requires intact molecules.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=92568Documentos Relacionados
- Activity of Free and Clay-Bound Insecticidal Proteins from Bacillus thuringiensis subsp. israelensis against the Mosquito Culex pipiens
- Adsorption of plasmid DNA to mineral surfaces and protection against DNase I.
- Protection of expressed immunoglobulin genes against nuclease cleavage.
- Protection against malaria by immunization with plasmid DNA encoding circumsporozoite protein.
- Spermine and spermidine protection of plasmid DNA against single-strand breaks induced by singlet oxygen.
