Distribution of the partitioning protein KorB on the genome of IncP-1 plasmid RK2.
The ParB family partitioning protein, KorB, of plasmid RK2 is central to a regulatory network coordinating replication, maintenance and transfer genes. Previous immunofluorescence microscopy indicated that the majority of KorB is localized in plasmid foci. The 12 identified KorB binding sites on RK2 are differentiated by: position relative to promoters; binding strength; and cooperativity with other repressors and so the distribution of KorB may be sequestered around a sub-set of sites. However, chromatin immunoprecipitation analysis showed that while RK2 DNA molecules appear to sequester KorB to create a higher local concentration, cooperativity between DNA binding proteins does not result in major differences in binding site occupancy. Thus under steady state conditions all operators are close to fully occupied and this correlates with gene expression on the plasmid being highly repressed.
Chiu
Chung-Min
CM
School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK.
Manzoor
Susan E
SE
Batt
Sarah M
SM
Muntaha
Sidra tul
St
Bingle
Lewis E H
LE
Thomas
Christopher M
CM
D001426:Bacterial Proteins / Q000737:chemistry*; D001665:Binding Sites; D047369:Chromatin Immunoprecipitation; D004247:DNA / Q000737:chemistry / Q000235:genetics; D004926:Escherichia coli / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D020868:Gene Silencing; D017930:Genes, Reporter; D016680:Genome, Bacterial; D047468:Immunoprecipitation; D008957:Models, Genetic; D010957:Plasmids / Q000378:metabolism; D011485:Protein Binding; D016958:Pseudomonas putida / Q000378:metabolism; D027981:Symporters / Q000378:metabolism
D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; C053863:KorB protein, Plasmid RK2; D027981:Symporters; C033903:xylE protein, E coli; D004247:DNA