Send to

Choose Destination
J Bacteriol. 2009 Feb;191(3):720-7. doi: 10.1128/JB.01257-08. Epub 2008 Nov 21.

Lagging-strand DNA replication origins are required for conjugal transfer of the promiscuous plasmid pMV158.

Author information

Department of Protein Science, Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas, Ramiro de Maeztu 9, E-28040 Madrid, Spain.


The promiscuous streptococcal plasmid pMV158 is mobilizable by auxiliary plasmids and replicates by the rolling-circle mechanism in a variety of bacterial hosts. The plasmid has two lagging-strand origins, ssoA and ssoU, involved in the conversion of single-stranded DNA intermediates into double-stranded plasmid DNA during vegetative replication. Transfer of the plasmid also would involve conversion of single-stranded DNA molecules into double-stranded plasmid forms in the recipient cells by conjugative replication. To test whether lagging-strand origins played a role in horizontal transfer, pMV158 derivatives defective in one or in both sso's were constructed and tested for their ability to colonize new hosts by means of intra- and interspecies mobilization. Whereas either sso supported transfer between strains of Streptococcus pneumoniae, only plasmids that had an intact ssoU could be efficiently mobilized from S. pneumoniae to Enterococcus faecalis. Thus, it appears that ssoU is a critical factor for pMV158 promiscuity and that the presence of a functional sso plays an essential role in plasmid transfer.

[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for HighWire Icon for PubMed Central
Loading ...
Support Center