title: SopB protein-mediated silencing of genes linked to the sopC locus of Escherichia coli F plasmid.
abstract: Expression of a high level of F-plasmid-encoded SopB protein in Escherichia coli is found to repress genes linked to sopC, a sequence element of F consisting of 12 tandemly joined imperfect repeats of a 43-bp motif. Repression of a gene can occur over a distance of at least 10 kb from the sopC element and is not affected by the relative orientation of sopC. In the repressed state, accessibility of intracellular DNA to cellular proteins is greatly reduced in the region containing sopC, as monitored by the trapping of the covalent intermediate between DNA and DNA gyrase and by Dam methylase-catalyzed DNA methylation. These results signify the formation of a nucleoprotein structure emanating from sopC and are discussed in terms of position-dependent silencing of genes in general and the IncG type of plasmid incompatibility in particular.
authors.affiliation: Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138.
authors.forename: A S
authors.initials: AS
authors.lastname: Lynch
authors.forename: J C
authors.initials: JC
authors.lastname: Wang
mesh_terms: D000667:Ampicillin / Q000494:pharmacology; D001426:Bacterial Proteins / Q000378:metabolism*; D001483:Base Sequence; D002701:Chloramphenicol / Q000494:pharmacology; D002874:Chromosome Mapping; D017931:DNA Primers; D004269:DNA, Bacterial / Q000378:metabolism; D004352:Drug Resistance, Microbial; D004926:Escherichia coli / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D029968:Escherichia coli Proteins; D005144:F Factor; D005798:Genes, Bacterial; D007544:Isopropyl Thiogalactoside / Q000494:pharmacology; D008780:Methyltransferases / Q000378:metabolism; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D012329:RNA, Bacterial / Q000096:biosynthesis; D012333:RNA, Messenger / Q000096:biosynthesis; D015265:Site-Specific DNA-Methyltransferase (Adenine-Specific); D013489:Suppression, Genetic; D013752:Tetracycline / Q000494:pharmacology
chemical_list: D001426:Bacterial Proteins; D017931:DNA Primers; D004269:DNA, Bacterial; D029968:Escherichia coli Proteins; D012329:RNA, Bacterial; D012333:RNA, Messenger; C060972:SopB protein, Bacteria; C489223:SopB protein, E coli; D007544:Isopropyl Thiogalactoside; D002701:Chloramphenicol; D000667:Ampicillin; D008780:Methyltransferases; C058693:Dam methyltransferase; D015265:Site-Specific DNA-Methyltransferase (Adenine-Specific); C499294:dam protein, E coli; D013752:Tetracycline