The secret life of conjugative relaxases
Publication date: Available online 17 May 2019Source: PlasmidAuthor(s): Dolores Lucía Guzmán-Herrador, Matxalen LlosaAbstractConjugative relaxases are well-characterized proteins responsible for the site- and strand-specific endonucleolytic cleavage and strand transfer reactions taking place at the start and end of the conjugative DNA transfer process. Most of the relaxases characterized biochemically and structurally belong to the HUH family of endonucleases. However, an increasing number of new families of relaxases are revealing a variety of protein folds and catalytic alternatives to accomplish conjugative DNA proces...
Source: Plasmid - May 18, 2019 Category: Biotechnology Source Type: research

Delineation of the integrase-attachment and origin-of-transfer regions of the symbiosis island ICEMlSymR7A
Publication date: Available online 9 May 2019Source: PlasmidAuthor(s): Callum J. Verdonk, John T. Sullivan, Kate M. Williman, Leila Nicholson, Tahlia R. Bastholm, Michael F. Hynes, Clive W. Ronson, Charles S. Bond, Joshua P. RamsayAbstractIntegrative and conjugative elements (ICEs) are chromosomally-integrated mobile genetic elements that excise from their host chromosome and transfer to other bacteria via conjugation. ICEMlSymR7A is the prototypical member of a large family of “symbiosis ICEs” which confer upon their hosts the ability to form a nitrogen-fixing symbiosis with a variety of legume species. Mesorhizobial ...
Source: Plasmid - May 10, 2019 Category: Biotechnology Source Type: research

Escherichia coli vectors having stringently repressible replication origins allow a streamlining of Crispr/Cas9 gene editing
This study describes the construction of an expanded series of plasmid vectors having replication origins of p15a, RSF1030 or RSF1031 that like pAM34 have IPTG-dependent replication. Surprisingly, these plasmids can be cured in fewer generations than pAM34. Derivatives of pAM34 with alternative antibiotic selection markers were also constructed. The utility of these vectors is demonstrated in the construction of a CRISPR-Cas9 system consisting of an IPTG-dependent Cas9 plasmid and a curable guide RNA plasmid having a streptomycin counterselection marker. This system was successfully demonstrated by construction of point mu...
Source: Plasmid - May 1, 2019 Category: Biotechnology Source Type: research

Molecular and genetic characterization of the pOV plasmid from Pasteurella multocida and construction of an integration vector for Gallibacterium anatis
ConclusionThe pOV plasmid is a wide-range, low-copy-number plasmid that is able to replicate in some gamma-proteobacteria. Part of this plasmid was integrated into the G. anatis 12656-12 chromosome. This construct may prove to be a useful tool for genetic studies of G. anatis. (Source: Plasmid)
Source: Plasmid - April 23, 2019 Category: Biotechnology Source Type: research

Mobilisation of a small Acinetobacter plasmid carrying an oriT transfer origin by conjugative RepAci6 plasmids
Publication date: Available online 11 April 2019Source: PlasmidAuthor(s): Grace A. Blackwell, Ruth M. HallAbstractMost Acinetobacter plasmids are genus specific but their properties have not been investigated. Small plasmids with Rep_3 family replication initiation proteins and iterons are common in Acinetobacter baumannii and often carry antibiotic resistance genes and toxin-antitoxin systems. A RepAci1 plasmid, carrying the carbapenem resistance gene oxa23 in Tn2006 and a RepAci2 plasmid carrying the amikacin (kanamycin and neomycin) resistance gene aphA6 in TnaphA6 were identified. These two plasmids have related rep re...
Source: Plasmid - April 13, 2019 Category: Biotechnology Source Type: research

Editorial Board
Publication date: March 2019Source: Plasmid, Volume 102Author(s): (Source: Plasmid)
Source: Plasmid - April 12, 2019 Category: Biotechnology Source Type: research

A simple dual-inducible CRISPR interference system for multiple gene targeting in Corynebacterium glutamicum
Publication date: Available online 4 April 2019Source: PlasmidAuthor(s): Rahul Gauttam, Gerd M. Seibold, Phillipp Mueller, Tatjana Weil, Tamara Weiß, René Handrick, Bernhard J. EikmannsAbstractThe development of CRISPR interference (CRISPRi) technology has dramatically increased the pace and the precision of target identification during platform strain development. In order to develop a simple, reliable, and dual-inducible CRISPRi system for the industrially relevant Corynebacterium glutamicum, we combined two different inducible repressor systems in a single plasmid to separately regulate the expression of dCas9 (anhydr...
Source: Plasmid - April 5, 2019 Category: Biotechnology Source Type: research

De novo synthesis of the complete genome of coxsackievirus A10 based on Golden Gate cloning combined with promoter reconstruction
Publication date: Available online 27 March 2019Source: PlasmidAuthor(s): Meng Li, Xinguo Li, Xiaoqi Chen, Shuo ShenAbstractIn the present study, a donor plasmid derived from pUC19 and two recipient plasmids, which had been modified from the donor plasmid and contained the red fluorescence protein gene mCherry as a reporter gene downstream of the hybrid tac promoter with the −35 region deletion mutation, were constructed. The complete genome sequence of coxsackievirus A10 downstream of a T7 promoter was divided into 7 fragments and synthesized with overlap extension PCR and the DNAworks program. Then, using the Golden Ga...
Source: Plasmid - March 28, 2019 Category: Biotechnology Source Type: research

Don't overlook the little guy: An evaluation of the frequency of small plasmids co-conjugating with larger carbapenemase gene containing plasmids
Publication date: Available online 27 March 2019Source: PlasmidAuthor(s): Katie Barry, Alexander M. Wailan, Anna E. Sheppard, Derrick Crook, Kasi Vegesana, Nicole Stoesser, Hardik I. Parikh, Robert Sebra, Amy J. MathersAbstractAs the spread of antimicrobial resistance (AMR) genes becomes an increasing global threat, improved understanding of mobile genetic elements which contribute to the spread of antimicrobial resistance genes, becomes more critical. We created transconjugants from the mating of three chromosomally isogenic Klebsiella pneumoniae carbapenemase (blaKPC) positive Citrobacter freundii isolates with a laborat...
Source: Plasmid - March 28, 2019 Category: Biotechnology Source Type: research

Insight into the structure, function and conjugative transfer of pLPU83a, an accessory plasmid of Rhizobium favelukesii LPU83
In this study, we analyzed rhizobial plasmids classified according to their TraR regulators into four different groups. Each group has a particular genomic architecture. In one of the groups (I-C), represented by pLPU83a from Rhizobium favelukesii LPU83, CT induction requires TraR. With manual annotation, a traI was located in the plasmid distant to the traR gene. These features make pLPU83a an interesting plasmid for studying novel mechanisms of CT regulation. We mutagenized the traI gene, and found that it does not participate in CT regulation. Furthermore, we studied whether pLPU83a is subject to QS regulation by determ...
Source: Plasmid - March 28, 2019 Category: Biotechnology Source Type: research

The shufflon of IncI1 plasmids is rearranged constantly during different growth conditions
Publication date: Available online 15 March 2019Source: PlasmidAuthor(s): Michael S.M. Brouwer, Stephanie D. Jurburg, Frank Harders, Arie Kant, Dik J. Mevius, Adam P. Roberts, Alex BossersAbstractOne of the factors that can affect conjugation of IncI1 plasmids, amongst others, is the genetic region known as the shufflon. This multiple inversion system modifies the pilus tip proteins used during conjugation, thus affecting the affinity for different recipient cells. Although recombination is known to occur in in vitro conditions, little is known about the regulation and the extend of recombination that occurs. To measure th...
Source: Plasmid - March 16, 2019 Category: Biotechnology Source Type: research

Identification of a novel lineage of plasmids within phylogenetically diverse subclades of IncHI2-ST1 plasmids
Publication date: Available online 15 March 2019Source: PlasmidAuthor(s): Piklu Roy Chowdhury, Mathieu Fourment, Matthew Z. DeMaere, Leigh Monahan, John Merlino, Thomas Gottlieb, Aaron E. Darling, Steven P. DjordjevicAbstractIncHI2-ST1 plasmids play an important role in co-mobilizing genes conferring resistance to critically important antibiotics and heavy metals. Here we present the identification and analysis of IncHI2-ST1 plasmid pSPRC-Echo1, isolated from an Enterobacter hormaechei strain from a Sydney hospital, which predates other multi-drug resistant IncHI2-ST1 plasmids reported from Australia. Our time-resolved phy...
Source: Plasmid - March 16, 2019 Category: Biotechnology Source Type: research

Original Research Article - Conjugative and replicative biology of the Staphylococcus aureus antimicrobial resistance plasmid, pC02
Publication date: Available online 4 March 2019Source: PlasmidAuthor(s): Patrick T. LaBreck, Zhaozhang Li, Kevin P. Gibbons, D. Scott MerrellAbstractGenetic transfer among bacteria propels rapid resistance to antibiotics and decreased susceptibility to antiseptics. Staphylococcus aureus is a common culprit of hospital and community acquired infections, and S. aureus plasmids have been shown to carry a multitude of antimicrobial resistance genes. We previously identified a novel conjugative, multidrug resistance plasmid, pC02, from the clinical S. aureus isolate C02. This plasmid contained the chlorhexidine resistance gene ...
Source: Plasmid - March 5, 2019 Category: Biotechnology Source Type: research

Analysis of two B/O plasmids, R805a from 1972 and pCERC6 from 2008, reveals extensive mosaicism in B/O plasmid backbones
Publication date: Available online 27 February 2019Source: PlasmidAuthor(s): Robert A. Moran, Isabella A. Richardson, Ruth M. HallAbstractTwo B/O plasmids were sequenced. The kanamycin resistance plasmid R805a was found in a Salmonella Typhi strain from a 1972 typhoid fever outbreak in Mexico City. pCERC6, which confers resistance to ampicillin, streptomycin and sulphamethoxazole, was found in a commensal E. coli isolated from a healthy adult in Sydney in 2008. Both plasmids contain the same gene for RNAI, the incompatibility determinant, as the reference B/O plasmid pMU707 and the recently reported plasmid p838B-R, which ...
Source: Plasmid - February 28, 2019 Category: Biotechnology Source Type: research

pXO16, the large conjugative plasmid from Bacillus thuringiensis serovar israelensis displays an extended host spectrum
Publication date: Available online 27 February 2019Source: PlasmidAuthor(s): Pauline Hinnekens, Klèma Marcel Koné, Nancy Fayad, Audrey Leprince, Jacques MahillonAbstractpXO16, the large conjugative plasmid from Bacillus thuringiensis serovar israelensis is able to efficient self-transfer, to mobilize and retro-mobilize non-conjugative plasmids, including “non-mobilizable” plasmids, and to transfer chromosomal loci. It also displays a remarkable aggregation phenotype associated with conjugation under liquid conditions. However, it was recently shown that aggregation boosts pXO16 transfer but is not mandatory. In this ...
Source: Plasmid - February 28, 2019 Category: Biotechnology Source Type: research