Plasmid ColE1 incompatibility determined by interaction of RNA I with primer transcript.
AUTOR(ES)
Tomizawa, J
RESUMO
Mutants of plasmid pNT7 that can coexist with plasmid pMB9 in growing bacteria have been isolated. These mutants show altered incompatibility properties and increased copy numbers. Each mutant has a single base change at or near the center of one of the three palindromes in the region that specifies two RNA species: a larger one (primer transcripts) that provides a primer for DNA replication and a smaller one (RNA I) that is the incompatibility-specific inhibitor of primer formation. In vitro transcription studies show that the single base changes affect both the ability of RNA I to inhibit primer formation and the sensitivity of primer formation to inhibition by RNA I. RNA I hybridizes to the primer transcript, and the rate of hybridization is reduced by the single base changes. Based on analyses of inhibition of in vitro primer formation by RNA I and of in vivo properties of the mutant plasmids, we conclude that incompatibility between two plasmids can be attributed to inhibition of primer formation on one of the plasmids by the RNA I of the other. Inhibition of primer formation by RNA I appears to be the mechanism that determines the copy number of pNT7 and its derivatives.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=348984Documentos Relacionados
- Characterization of the ColE1 primer-RNA1 complex: analysis of a domain of ColE1 RNA1 necessary for its interaction with primer RNA.
- Inhibition of ColE1 RNA primer formation by a plasmid-specified small RNA.
- ColE1 Plasmid Incompatibility: Localization and Analysis of Mutations Affecting Incompatibility
- ColE1 plasmid incompatibility: localization and analysis of mutations affecting incompatibility.
- Effect of altering GATC sequences in the plasmid ColE1 primer promoter.