title: Functional analysis of the finO distal region of plasmid R1.
abstract: The intergenic region linking conjugative transfer and replication copy control modules of IncF plasmids shows conservation of gene homology and organization. Genes distal to finO are coordinately expressed with the upstream transfer operon encoding the majority of conjugation genes in related plasmids. Here we investigate potential functions for these genes in copy number control and in processes related to conjugation: gene transfer, pilus specific phage infection and plasmid-promoted biofilm formation by an Escherichia coli host. We find that insertional inactivation of genes in the finO distal region reduced transcriptional read through into the downstream copB gene of plasmid R1. The mutant plasmid derivatives exhibited a reduced copy number compared to the wild type. Moreover all insertion mutant derivatives of plasmid R1-16 with aberrantly low copy numbers conferred poor biofilm forming ability to their hosts. The general mutagenesis thus identified plasmid stability genes as the only plasmid functions besides conjugation genes linked to plasmid-promoted biofilm production under these laboratory conditions. Our findings imply that a novel component of cis- or trans-regulation on the transcriptional level is important to normal R1 plasmid copy number regulation.
authors.affiliation: University of Graz, Institute of Molecular Biosciences, Humboldtstrasse 50, A-8010 Graz, Austria.
authors.forename: Monika R
authors.initials: MR
authors.lastname: Nuk
authors.forename: Andreas
authors.initials: A
authors.lastname: Reisner
authors.forename: Martina
authors.initials: M
authors.lastname: Neuwirth
authors.forename: Katrin
authors.initials: K
authors.lastname: Schilcher
authors.forename: Roland
authors.initials: R
authors.lastname: Arnold
authors.forename: Andre
authors.initials: A
authors.lastname: Jehl
authors.forename: Thomas
authors.initials: T
authors.lastname: Rattei
authors.forename: Ellen L
authors.initials: EL
authors.lastname: Zechner
mesh_terms: D018441:Biofilms / Q000254:growth & development; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D029968:Escherichia coli Proteins / Q000235:genetics* / Q000378:metabolism*; D018628:Gene Dosage; D015964:Gene Expression Regulation, Bacterial; D023061:Gene Order; D008969:Molecular Sequence Data; D016296:Mutagenesis; D016254:Mutagenesis, Insertional; D009154:Mutation; D010641:Phenotype; D011815:R Factors / Q000235:genetics* / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism*; D012097:Repressor Proteins / Q000235:genetics* / Q000378:metabolism*
chemical_list: D029968:Escherichia coli Proteins; D016601:RNA-Binding Proteins; D012097:Repressor Proteins; C074275:FinO protein, E coli