Effect of the CopB Auxiliary Replication Control System on Stability of Maintenance of Par+ Plasmid R1
AUTOR(ES)
Olsson, Jan A.
FONTE
American Society for Microbiology
RESUMO
Plasmid R1 is a low-copy-number plasmid that is present at a level of about four or five copies per average cell. The copy number is controlled posttranscriptionally at the level of synthesis of the rate-limiting initiator protein RepA. In addition to this, R1 has an auxiliary system that derepresses a second promoter at low copy numbers, leading to increased repA mRNA synthesis. This promoter is normally switched off by a constitutively synthesized plasmid-encoded repressor protein, CopB; in cells with low copy numbers, the concentration of CopB is low and the promoter is derepressed. Here we show that the rate of loss of a Par+ derivative of the basic replicon of R1 increased about sevenfold when the cells contained a high concentration of the CopB protein formed from a compatible plasmid.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=303431Documentos Relacionados
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