Reconstitutions of plasmid partition systems and their mechanisms
Publication date: Available online 18 March 2017 Source:Plasmid Author(s): Adam C. Brooks, Ling Chin Hwang Bacterial plasmid and chromosome segregation systems ensure that genetic material is efficiently transmitted to progeny cells. Cell-based studies have shed light on the dynamic nature and the molecular basis of plasmid partition systems. In vitro reconstitutions, on the other hand, have proved to be an invaluable tool for studying the minimal components required to elucidate the mechanism of DNA segregation. This allows us to gain insight into the biological and biophysical processes that enable bacterial cells to...
Source: Plasmid - March 18, 2017 Category: Biotechnology Source Type: research
The replication protein of pHW126 auto-controls its expression
Publication date: Available online 11 March 2017 Source:Plasmid Author(s): Wilfried Rozhon pHW126 belongs to a small group of rolling circle plasmids. So far, the region mediating autonomous replication has been identified and it was shown that the rep gene is required for replication. However, the regulation of rep expression remained elusive. Here evidence is presented that expression of the replication gene rep is auto-regulated. Sequence analysis revealed a conserved stretch in the rep promoter consisting of three imperfect direct repeats (DR2.1, DR2.2 and DR2.3). Assays for promoter activity showed that these direc...
Source: Plasmid - March 10, 2017 Category: Biotechnology Source Type: research
Ordering the mob: Insights into replicon and MOB typing schemes from analysis of a curated dataset of publicly available plasmids
Publication date: Available online 9 March 2017 Source:Plasmid Author(s): Alex Orlek, Hang Phan, Anna E. Sheppard, Michel Doumith, Matthew Ellington, Tim Peto, Derrick Crook, A. Sarah Walker, Neil Woodford, Muna F. Anjum, Nicole Stoesser Plasmid typing can provide insights into the epidemiology and transmission of plasmid-mediated antibiotic resistance. The principal plasmid typing schemes are replicon typing and MOB typing, which utilize variation in replication loci and relaxase proteins respectively. Previous studies investigating the proportion of plasmids assigned to a type by these schemes (‘typeabilit...
Source: Plasmid - March 9, 2017 Category: Biotechnology Source Type: research
The Tcp conjugation system of Clostridium perfringens
Publication date: Available online 7 March 2017 Source:Plasmid Author(s): Jessica A. Wisniewski, Julian I. Rood The Gram-positive pathogen Clostridium perfringens possesses a family of large conjugative plasmids that is typified by the tetracycline resistance plasmid pCW3. Since these plasmids may carry antibiotic resistance genes or genes encoding extracellular or sporulation-associated toxins, the conjugative transfer of these plasmids appears to be important for the epidemiology of C. perfringens-mediated diseases. Sequence analysis of members of this plasmid family identified a highly conserved 35kb region that enc...
Source: Plasmid - March 7, 2017 Category: Biotechnology Source Type: research
Carriage of type II toxin-antitoxin systems by the growing group of IncX plasmids
Publication date: Available online 3 March 2017 Source:Plasmid Author(s): Paula Bustamante, Jonathan R. Iredell The stable maintenance of certain plasmids in bacterial populations has contributed significantly to the current worldwide antibiotic resistance (AbR) emergency. IncX plasmids, long underestimated in this regard, have achieved recent notoriety for their roles in transmission of resistance to carbapenem and colistin, the last–line antibiotics for Gram-negative infections. Toxin-antitoxin (TA) systems contribute to stable maintenance of many AbR plasmids, and a few TA systems have been previously described in...
Source: Plasmid - March 3, 2017 Category: Biotechnology Source Type: research
Characterization of the cryptic plasmid pOfk55 from Legionella pneumophila and construction of a pOfk55-derived shuttle vector
In this study, a cryptic plasmid pOfk55 from Legionella pneumophila was isolated and characterized. pOfk55 comprised 2584bp with a GC content of 37.3% and contained three putative open reading frames (ORFs). orf1 encoded a protein of 195 amino acids and the putative protein shared 39% sequence identity with a putative plasmid replication protein RepL. ORF1 was needed for replication in L. pneumophila but pOfk55 did not replicate in Escherichia coli. orf2 and orf3 encoded putative hypothetical proteins of 114 amino acids and 78 amino acids, respectively, but the functions of the putative proteins ORF2 and OFR3 are not clear...
Source: Plasmid - March 1, 2017 Category: Biotechnology Source Type: research
Spatial distribution of high copy number plasmids in bacteria
Publication date: Available online 2 March 2017 Source:Plasmid Author(s): Yong Wang Plasmids play essential roles in bacterial metabolism, evolution, and pathogenesis. The maintenance of plasmids is of great importance both scientifically and practically. In this mini-review, I look at the problem from a slightly different point of view and focus on the spatial distribution of high copy number plasmids, for which no active segregation mechanism has been identified. I review several distribution models and summarize the direct and indirect evidence in the literature, including the most recent progress on measuring the sp...
Source: Plasmid - March 1, 2017 Category: Biotechnology Source Type: research
An extra repABC locus in the incRh2 Ti plasmid pTiBo542 exerts incompatibility toward an incRh1 plasmid
Publication date: Available online 24 February 2017 Source:Plasmid Author(s): Shinji Yamamoto, Vita Agustina, Ayako Sakai, Kazuki Moriguchi, Katsunori Suzuki Ti/Ri plasmids in pathogenic Agrobacterium species are repABC replicons that are stably maintained by the function of repABC genes. Two Ti plasmids, pTiBo542 and pTiS4, belonging to incRh2 and incRh4 incompatibility groups, respectively, were reported to carry two repABC loci. In the present study, to reveal the roles of the two repABC loci in the two plasmids, we constructed mini-replicons carrying any one or both of the repABC loci (referred to as repABC1 and...
Source: Plasmid - February 23, 2017 Category: Biotechnology Source Type: research
Conjugative type IV secretion in Gram-positive pathogens: TraG, a lytic transglycosylase and endopeptidase, interacts with translocation channel protein TraM
Publication date: Available online 17 February 2017 Source:Plasmid Author(s): Verena Kohler, Ines Probst, Andreas Aufschnaiter, Sabrina Büttner, Lisa Schaden, Gerald Rechberger, Günther Koraimann, Elisabeth Grohmann, Walter Keller Conjugative transfer plays a major role in the transmission of antibiotic resistance in bacteria. pIP501 is a Gram-positive conjugative model plasmid with the broadest transfer host-range known so far and is frequently found in Enterococcus faecalis and Enterococcus faecium clinical isolates. The pIP501 type IV secretion system is encoded by 15 transfer genes. In this work, we focus ...
Source: Plasmid - February 16, 2017 Category: Biotechnology Source Type: research
Episomal lentiviral vectors confer erythropoietin expression in dividing cells
In conclusion, the NIL vector based on an S/MAR sequence retained the extrachromosomal expression of a therapeutic gene in dividing cells. Our results show that NIL vectors maybe a safe and effective means of gene delivery, which is of potential clinical significance. (Source: Plasmid)
Source: Plasmid - February 8, 2017 Category: Biotechnology Source Type: research
Comparative analysis of the standard PCR-Based Replicon Typing (PBRT) with the commercial PBRT-KIT
Publication date: Available online 27 January 2017 Source:Plasmid Author(s): Elisa Carloni, Francesca Andreoni, Enrica Omiccioli, Laura Villa, Mauro Magnani, Alessandra Carattoli Plasmids are the main vectors of resistance and virulence genes in Enterobacteriaceae and plasmid typing is essential for the analysis of evolution, epidemiology and spread of antibacterial resistance. The PCR-Based Replicon Typing (PBRT), developed by Carattoli et al. in 2005, was an efficient method for plasmid identification and typing in Enterobacteriaceae. The 2005 PBRT scheme detected 18 replicons in 8 PCR reactions. Recently, the id...
Source: Plasmid - January 27, 2017 Category: Biotechnology Source Type: research
Construction of a BioBrick ™ compatible vector system for Rhodococcus
In this report we describe our progress toward developing a BioBrick™ compatible plasmid system for Rhodococcus. We demonstrate its utility for heterologous protein expression through flow cytometric analysis of the lac promoter in the oleaginous strain Rhodococcus opacus PD630. (Source: Plasmid)
Source: Plasmid - January 23, 2017 Category: Biotechnology Source Type: research
Baculovirus-based genome editing in primary cells
Publication date: Available online 22 January 2017 Source:Plasmid Author(s): Maysam Mansouri, Zahra Ehsaei, Verdon Taylor, Philipp Berger Genome editing in eukaryotes became easier in the last years with the development of nucleases that induce double strand breaks in DNA at user-defined sites. CRISPR/Cas9-based genome editing is currently one of the most powerful strategies. In the easiest case, a nuclease (e.g. Cas9) and a target defining guide RNA (gRNA) are transferred into a target cell. Non-homologous end joining (NHEJ) repair of the DNA break following Cas9 cleavage can lead to inactivation of the target gene....
Source: Plasmid - January 22, 2017 Category: Biotechnology Source Type: research
A plasmid-encoded DsbA homologue is a growth-phase regulated thioredoxin
Publication date: Available online 4 January 2017 Source:Plasmid Author(s): Amada Díaz-Magaña, Martha P. Chávez-Moctezuma, Jesús Campos-García, Martha I. Ramírez-Díaz, Carlos Cervantes The Pseudomonas aeruginosa plasmid pUM505 contains in a pathogenicity island the dsbA2 gene, which encodes a product with similarity to DsbA protein disulfide isomerases, enzymes that catalyze formation and isomerization of disulfide bonds in protein cysteine residues. Using transcriptional fusions, it was found that dsbA2 gene promoter is activated during the stationary phase, suggesting that DsbA2 protein may be required for ...
Source: Plasmid - January 4, 2017 Category: Biotechnology Source Type: research
BIBAC-GW-based vectors for generating reporter lines for site-specific genome editing in planta
Publication date: Available online 26 December 2016 Source:Plasmid Author(s): Damar Tri Anggoro, Mariliis Tark-Dame, Aimee Walmsley, Rurika Oka, Mara de Sain, Maike Stam When generating transgenic plants, one of the objectives is to achieve stable expression of the transgene. Transgene silencing can be avoided by single copy integration of the transgene. Binary systems that predominantly result in single copy integrations, such as BIBAC vectors, are also single-copy in E. coli, the organism in which the T-DNA to be delivered to the plant is assembled. Although a low-copy number is important for stable maintenance o...
Source: Plasmid - December 26, 2016 Category: Biotechnology Source Type: research
