Dataset Information

Gene 19 of plasmid R1 is required for both efficient conjugative DNA transfer and bacteriophage R17 infection.

ABSTRACT: F-like plasmids require a number of genes for conjugation, including tra operon genes and genes traM and traJ, which lie outside the tra operon. We now establish that a gene in the "leading region," gene 19, provides an important function during conjugation and RNA phage infection. Mutational inactivation of gene 19 on plasmid R1-16 by introduction of two nonpolar stop codons results in a 10-fold decrease in the conjugation frequency. Furthermore, infection studies with the male-specific bacteriophage R17 revealed that the phage is not able to form clear plaques in Escherichia coli cells carrying an R1-16 plasmid with the defective copy of gene 19. The total number of cells infected by phage R17 is reduced by a factor of 10. Both the conjugation- and infection-attenuated phenotypes caused by the defective gene 19 can be complemented in trans by introducing gene 19 alleles encoding the wild-type protein. Restoration of the normal phenotypes is also possible by introduction of the pilT gene encoded by the unrelated IncI plasmid R64. Our functional studies and similarities of protein 19 to proteins encoded by other DNA transfer systems, as well as the presence of a conserved motif in all of these proteins (indicative for a putative muramidase activity) suggest that protein 19 of plasmid R1 facilitates the passage of DNA during conjugation and entry of RNA during phage infection.

SUBMITTER: Bayer M

PROVIDER: S-EPMC177174 | biostudies-other | 1995 Aug

REPOSITORIES: biostudies-other

ACCESS DATA

Publications

Gene 19 of plasmid R1 is required for both efficient conjugative DNA transfer and bacteriophage R17 infection.

Bayer M M Eferl R R Zellnig G G Teferle K K Dijkstra A A Koraimann G G Högenauer G G

Journal of bacteriology 19950801 15

F-like plasmids require a number of genes for conjugation, including tra operon genes and genes traM and traJ, which lie outside the tra operon. We now establish that a gene in the "leading region," gene 19, provides an important function during conjugation and RNA phage infection. Mutational inactivation of gene 19 on plasmid R1-16 by introduction of two nonpolar stop codons results in a 10-fold decrease in the conjugation frequency. Furthermore, infection studies with the male-specific bacteri ...[more]

PMID: 7543471

Similar Datasets

Project description:Multiwalled carbon nanotubes (MWCNTs) regularly enter aquatic environments due to their ubiquity in consumer products and engineering applications. However, the effects of MWCNT pollution on the environmental microbiome are poorly understood. Here, we evaluated whether these carbon nanoparticles can elevate the spread of antimicrobial resistance by promoting bacterial plasmid transfer, which has previously been observed for copper nanomaterials with antimicrobial properties as well as for microplastics. Through a combination of experimental liquid mating assays between Pseudomonas putida donor and recipient strains with plasmid pKJK5::gfpmut3b and mathematical modeling, we here demonstrate that the presence of MWCNTs leads to increased plasmid transfer rates in a concentration-dependent manner. The percentage of transconjugants per recipient significantly increased from 0.21 ± 0.04% in absence to 0.41 ± 0.09% at 10 mg L-1 MWCNTs. Similar trends were observed when using an Escherichia coli donor hosting plasmid pB10. The identified mechanism underlying the observed dynamics was the agglomeration of MWCNTs. A significantly increased number of particles with >6 μm diameter was detected in the presence of MWCNTs, which can in turn provide novel surfaces for bacterial interactions between donor and recipient cells after colonization. Fluorescence microscopy confirmed that MWCNT agglomerates were indeed covered in biofilms that contained donor bacteria as well as elevated numbers of green fluorescent transconjugant cells containing the plasmid. Consequently, MWCNTs provide bacteria with novel surfaces for intense cell-to-cell interactions in biofilms and can promote bacterial plasmid transfer, hence potentially elevating the spread of antimicrobial resistance. IMPORTANCE In recent decades, the use of carbon nanoparticles, especially multiwalled carbon nanotubes (MWCNTs), in a variety of products and engineering applications has been growing exponentially. As a result, MWCNT pollution into environmental compartments has been increasing. We here demonstrate that the exposure to MWCNTs can affect bacterial plasmid transfer rates in aquatic environments, an important process connected to the spread of antimicrobial resistance genes in microbial communities. This is mechanistically explained by the ability of MWCNTs to form bigger agglomerates, hence providing novel surfaces for bacterial interactions. Consequently, increasing pollution with MWCNTs has the potential to elevate the ongoing spread of antimicrobial resistance, a major threat to human health in the 21st century.

Project description:Differential gene expression in biofilm cells suggests that adding the derepressed conjugative plasmid R1drd19 increases biofilm formation by affecting genes related to envelope stress (rseA and cpxAR), biofilm formation (bssR and cstA), energy production (glpDFK), acid resistance (gadABCEX and hdeABD), and cell motility (csgBEFG, yehCD, yadC, and yfcV); genes encoding outer membrane proteins (ompACF), phage shock proteins (pspABCDE), and cold shock proteins (cspACDEG); and phage-related genes. To investigate the link between the identified genes and biofilm formation upon the addition of R1drd19, 40 isogenic mutants were classified according to their different biofilm formation phenotypes. Cells with class I mutations (those in rseA, bssR, cpxA, and ompA) exhibited no difference from the wild-type strain in biofilm formation and no increase in biofilm formation upon the addition of R1drd19. Cells with class II mutations (those in gatC, yagI, ompC, cspA, pspD, pspB, ymgB, gadC, pspC, ymgA, slp, cpxP, cpxR, cstA, rseC, ompF, and yqjD) displayed increased biofilm formation compared to the wild-type strain but decreased biofilm formation upon the addition of R1drd19. Class III mutants showed increased biofilm formation compared to the wild-type strain and increased biofilm formation upon the addition of R1drd19. Cells with class IV mutations displayed increased biofilm formation compared to the wild-type strain but little difference upon the addition of R1drd19, and class V mutants exhibited no difference from the wild-type strain but increased biofilm formation upon the addition of R1drd19. Therefore, proteins encoded by the genes corresponding to the class I mutant phenotype are involved in R1drd19-promoted biofilm formation, primarily through their impact on cell motility. We hypothesize that the pili formed upon the addition of the conjugative plasmid disrupt the membrane (induce ompA) and activate the two-component system CpxAR as well as the other envelope stress response system, RseA-sigma(E), both of which, along with BssR, play a key role in bacterial biofilm formation.

Dataset Information

Gene 19 of plasmid R1 is required for both efficient conjugative DNA transfer and bacteriophage R17 infection.

Publications

Gene 19 of plasmid R1 is required for both efficient conjugative DNA transfer and bacteriophage R17 infection.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets