Cooperativity between KorB and TrbA Repressors of Broad-Host-Range Plasmid RK2
- 1 February 2001
- journal article
- Published by American Society for Microbiology in Journal of Bacteriology
- Vol. 183 (3) , 1022-31
- https://doi.org/10.1128/jb.183.3.1022-1031.2001
Abstract
The KorB and TrbA proteins of broad-host-range plasmid RK2 are key regulators of the plasmid genes required for conjugative transfer. trbBp is the primary promoter responsible for expression of mating pair formation genes. We show that despite the targets for KorB and TrbA at trbBp being about 165 bp apart, 189 bp upstream of the transcription start point and overlapping the −10 region, respectively, these two proteins show up to 10-fold cooperativity for the repression of trbBp . Deletion analysis of TrbA showed that the C-terminal domain (CTD), which has a high degree of sequence conservation with the CTD of KorA, is required for this cooperativity with KorB. Western blotting demonstrated that the apparently mutual enhancement of repression is not due simply to elevation of repressor level by the presence of the second protein, suggesting that the basis for cooperativity is interaction between KorB and TrbA bound at their respective operators.Keywords
This publication has 29 references indexed in Scilit:
- The hierarchy of KorB binding at its 12 binding sites on the broad-host-range plasmid RK2 and modulation of this binding by IncC1 protein 1 1Edited by J. KarnJournal of Molecular Biology, 2000
- Conserved C-terminal region of global repressor KorA of broad-host-range plasmid RK2 is required for co-operativity between KorA and a second RK2 global regulator, KorBJournal of Molecular Biology, 1999
- Silencing of Genes Flanking the P1 Plasmid CentromereScience, 1999
- Binding of phage Φ29 protein p4 to the early A2c promoter: recruitment of a repressor by the RNA polymeraseJournal of Molecular Biology, 1998
- Divergence and conservation of the partitioning and global regulation functions in the central control region of the IncP plasmids RK2 and R751Microbiology, 1997
- Purification of KorA Protein from Broad Host Range Plasmid RK2: Definition of a Hierarchy of KorA OperatorsJournal of Molecular Biology, 1995
- Regulation of transfer genes of promiscuous IncP plasmid RK2: repression of Tra1 region transcription both by relaxosome proteins and by the Tra2 regulator TrbAMicrobiology, 1994
- Complete Nucleotide Sequence of Birmingham IncPα PlasmidsJournal of Molecular Biology, 1994
- Conjugative transfer functions of broad‐host‐range plasmid RK2 are coregulated with vegetative replicationMolecular Microbiology, 1992
- Analysis of the trfA region of broad host-range plasmid RK2 by transposon mutagenesis and identification of polypeptide productsJournal of Molecular Biology, 1984