Global transcriptional regulator KorC coordinates expression of three backbone modules of the broad-host-range RA3 plasmid from IncU incompatibility group

Ludwiczak, Marta; Dolowy, Patrycja; Markowska, Aleksandra; Szarlak, Jolanta; Kulinska, Anna; Jagura-Burdzy, Grażyna

doi:10.1016/j.plasmid.2013.03.007

Cited by 18 publications

(38 citation statements)

References 50 publications

(69 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Between the replication and transfer genes there are three ORFs of unknown function that are present on all IncU plasmids. Since expression of these and several plasmid backbone genes was recently shown to be regulated by the plasmid-encoded protein KorC, we infer that these ORFs are also backbone genes (49). We propose that pMBUI3 consists entirely of IncU plasmid backbone genes.…”

Section: Resultsmentioning

confidence: 87%

Diverse Broad-Host-Range Plasmids from Freshwater Carry Few Accessory Genes

Brown

Sen

Yano

et al. 2013

Appl Environ Microbiol

View full text Add to dashboard Cite

c Broad-host-range self-transferable plasmids are known to facilitate bacterial adaptation by spreading genes between phylogenetically distinct hosts. These plasmids typically have a conserved backbone region and a variable accessory region that encodes host-beneficial traits. We do not know, however, how well plasmids that do not encode accessory functions can survive in nature. The goal of this study was to characterize the backbone and accessory gene content of plasmids that were captured from freshwater sources without selecting for a particular phenotype or cultivating their host. To do this, triparental matings were used such that the only required phenotype was the plasmid's ability to mobilize a nonconjugative plasmid. Based on complete genome sequences of 10 plasmids, only 5 carried identifiable accessory gene regions, and none carried antibiotic resistance genes. The plasmids belong to four known incompatibility groups (IncN, IncP-1, IncU, and IncW) and two potentially new groups. Eight of the plasmids were shown to have a broad host range, being able to transfer into alpha-, beta-, and gammaproteobacteria. Because of the absence of antibiotic resistance genes, we resampled one of the sites and compared the proportion of captured plasmids that conferred antibiotic resistance to their hosts with the proportion of such plasmids captured from the effluent of a local wastewater treatment plant. Few of the captured plasmids from either site encoded antibiotic resistance. A high diversity of plasmids that encode no or unknown accessory functions is thus readily found in freshwater habitats. The question remains how the plasmids persist in these microbial communities.

show abstract

Section: Resultsmentioning

confidence: 87%

Diverse Broad-Host-Range Plasmids from Freshwater Carry Few Accessory Genes

Brown

Sen

Yano

et al. 2013

Appl Environ Microbiol

View full text Add to dashboard Cite

show abstract

“…The concentration of the isolated DNA was determined with the NanoDrop 2000 instrument. Portions (20 ng) of the Cy5-labeled DNA fragments were incubated with increasing amounts of KorB or KorBA111T (20,40,60 …”

Section: Sds-page Analysis Of Korc and Mobc Overproductionmentioning

confidence: 99%

“…1 and 2A). The first one, IR-SnaBI-1 (RA3 coordinates 2075 to 2090) is located in the divergent orf02p/orf02prev promoter region (20) between the replication module and orf02, the first ORF of unknown function in the maintenance region (10). The previously described IRSnaBI-2 palindrome (RA3 coordinates 9707 to 9722), which is integral to parS, is adjacent to the promoter of the mobC-nic operon (conjugative module) (19) and close to the nick site in the oriT region.…”

Section: Partitioning Protein Korb (Ra3) Is a Transcriptional Repressormentioning

confidence: 99%

“…DQ401103) (10), and individual functional modules have been analyzed (18,19). The plasmid encodes a number of autoregulators, i.e., RepA and RepB in the replication module (10), KfrA and KorA in the maintenance module (18,20), and MobC in the conjugative transfer unit (19). KorC, encoded in the stability module, plays the role of a global transcriptional regulator controlling replication, maintenance, and conjugative transfer functions (10,20).…”

mentioning

confidence: 99%

“…The plasmid encodes a number of autoregulators, i.e., RepA and RepB in the replication module (10), KfrA and KorA in the maintenance module (18,20), and MobC in the conjugative transfer unit (19). KorC, encoded in the stability module, plays the role of a global transcriptional regulator controlling replication, maintenance, and conjugative transfer functions (10,20).In this paper, we reveal a regulatory role of the DNA-binding protein KorB (452 amino acids), which recognizes a specific sequence occurring in three RA3 locations (Fig. 1).…”

mentioning

confidence: 99%

See 2 more Smart Citations

Global Transcriptional Regulation of Backbone Genes in Broad-Host-Range Plasmid RA3 from the IncU Group Involves Segregation Protein KorB (ParB Family)

Kulinska

Godziszewska

Wojciechowska

et al. 2016

Appl Environ Microbiol

View full text Add to dashboard Cite

The KorB protein of the broad-host-range conjugative plasmid RA3 from the IncU group belongs to the ParB family of plasmid and chromosomal segregation proteins. As a partitioning DNA-binding factor, KorB specifically recognizes a 16-bp palindrome which is an essential motif in the centromere-like sequence parS RA3 , forms a segrosome, and together with its partner IncC (ParA family) participates in active DNA segregation ensuring stable plasmid maintenance. Here we show that by binding to this palindromic sequence, KorB also acts as a repressor for the adjacent mobC promoter driving expression of the mobC-nic operon, which is involved in DNA processing during conjugation. Three other promoters, one buried in the conjugative transfer module and two divergent promoters located at the border between the replication and stability regions, are regulated by KorB binding Large, low-copy-number plasmids displaying a broad host range (BHR) carry an extended backbone of operons involved in replication, copy number control, maintenance, and in the case of self-transmissible plasmids, also conjugative transfer. Expression of these genetic units is driven by high-activity promoters and therefore imposes a substantial metabolic cost on the bacterial cell. To minimize the metabolic burden to the host, regulatory networks have evolved to diminish the backbone gene expression to a low basal level while still allowing for rapid upregulation of the transcription when needed. The regulation is achieved by autogenous repressors that produce negative-feedback loops, mediumrange repressors that control particular modules, and globally acting regulators that bind operators scattered along the plasmid molecule to coordinate expression of all modules. Fine-tuning of gene expression is postulated to be achieved by the action of corepressors and their cooperative binding in the promoter regions, which makes the plasmid highly responsive and facilitates its adaptation (1-4).BHR plasmids from the incompatibility group IncU are widespread and ubiquitous in various aquatic environments, freshwater, fish farms, and clinical isolates (5-8). The modular-mosaic backbone of the IncU plasmids is extremely well conserved not only in its overall genetic organization but also at the nucleotide sequence level (8-10). The mosaic character of genomes from this group is demonstrated by homology of the functional blocks involved in replication, stable maintenance, and conjugative transfer to the respective functional modules of plasmids from different incompatibility groups. Thus, the stability region of RA3 encodes seven homologs of IncP-1 proteins (11), whereas the RA3 conjugative transfer region clusters with similarly organized modules from the PromA group of plasmids (12-16). The RA3 plasmid (Fig. 1), the group archetype isolated from the aquatic bacterium Aeromonas hydrophila (17), is the best-studied IncU representative. Its DNA sequence has been established (GenBank accession no. DQ401103) (10), and individual functional modules have been analyzed ...

show abstract

Plasmids and Their Hosts

Shintani

Suzuki

2019

DNA Traffic in the Environment

View full text Add to dashboard Cite

Global transcriptional regulator KorC coordinates expression of three backbone modules of the broad-host-range RA3 plasmid from IncU incompatibility group

Cited by 18 publications

References 50 publications

Diverse Broad-Host-Range Plasmids from Freshwater Carry Few Accessory Genes

Diverse Broad-Host-Range Plasmids from Freshwater Carry Few Accessory Genes

Global Transcriptional Regulation of Backbone Genes in Broad-Host-Range Plasmid RA3 from the IncU Group Involves Segregation Protein KorB (ParB Family)

Plasmids and Their Hosts

Contact Info

Product

Resources

About