Abstract:
:A number of plasmid-encoded gene systems are thought to stabilize plasmids by killing plasmid-free cells (also termed post-segregational killing or plasmid addiction). Here we analyse the mechanisms of plasmid stabilization by ccd of F, parDE of RP4 and parD of R1, and compare them to hok/sok of R1. To induce synchronous plasmid loss we constructed a novel plasmid replication-arrest system, which possesses the advantage that plasmid replication can be completely arrested by the addition of IPTG, a non-metabolizable inducer. Using isogenic plasmid constructions we have found, for the first time, consistent correlation between the effect on steady-state loss rates and the effect on cell proliferation in the plasmid replication-arrest assay for all three systems. The parDE system had the most pronounced effect both on plasmid stabilization and on plasmid retention after replication arrest. In contrast, ccd and parD both exhibited weaker effects than anticipated from previously published results. Thus, our results indicate that the function and efficiencies of some of the systems should be reconsidered. Our results are consistent with the previously postulated hypothesis that ccd and parDE act by killing plasmid-free segregants, whereas parD seems to act by inhibiting cell division of plasmid-free segregants.
journal_name
Mol Microbioljournal_title
Molecular microbiologyauthors
Jensen RB,Grohmann E,Schwab H,Díaz-Orejas R,Gerdes Kdoi
10.1111/j.1365-2958.1995.mmi_17020211.xsubject
Has Abstractpub_date
1995-07-01 00:00:00pages
211-20issue
2eissn
0950-382Xissn
1365-2958journal_volume
17pub_type
杂志文章abstract::During pathogenesis, Mycobacterium tuberculosis (Mtb) colonizes environments, such as the macrophage or necrotic granuloma, that are acidic and rich in cholesterol and fatty acids. The goal of this study was to examine how acidic pH and available carbon sources interact to regulate Mtb physiology. Here we report that ...
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pub_type: 评论,杂志文章
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pub_type: 杂志文章,评审
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更新日期:2000-12-01 00:00:00