Strong synthetic stationary phase promoter-based gene expression system for Escherichia coli
Publication date: Available online 5 February 2020Source: PlasmidAuthor(s): Jananee Jaishankar, Preeti SrivastavaAbstractThe Gram-negative bacterium Escherichia coli has been the work horse for recombinant protein production since the past several years. However, most of the gene expression systems used either require expensive inducers or exhibit low strength. In the present study, we have generated a strong promoter by repeated rounds of random mutagenesis in a stationary phase promoter isolated from Gordonia sp. IITR100. The promoter activity increased 16-fold as compared to the wild-type promoter. The resultant synthet...
Source: Plasmid - February 7, 2020 Category: Biotechnology Source Type: research
Cloning of pAhX22, a small cryptic plasmid from Aeromonas hydrophila, and construction of a pAhX22-derived shuttle vector
In this study, a cryptic plasmid from Aeromonas hydrophila (pAhX22) was cloned and characterized. pAhX22 was 2523 bp long, had a GC content of 59.9%, and contained two putative open reading frames (ORFs). orf1 and orf2 encoded putative proteins of 458 amino acids and 88 amino acids, respectively; these putative proteins might be involved in plasmid replication. An Escherichia coli–A. hydrophila shuttle vector, pAEsv-1 (4587 bp, KanR), was constructed using in-fusion cloning, combining pAhX22 with the kanamycin-resistance gene and the origin of replication from E. coli expression vector pET-28a. The transformation eff...
Source: Plasmid - January 30, 2020 Category: Biotechnology Source Type: research
The role of hosts, plasmids and environment in determining plasmid transfer rates: A meta-analysis
Publication date: Available online 10 January 2020Source: PlasmidAuthor(s): Richard J. Sheppard, Alice Beddis, Timothy G. BarracloughAbstractPlasmids transfer at highly variable rates which spread over 10 orders of magnitude. While rates have been measured for decades and it is known that the rates are affected by biotic and abiotic factors, it is unclear how and to what extent these factors determine the rates of transfer. We performed a meta-analysis of 1224 published transfer rates from 33 papers (filtered to 612 transfer rates) to assess this variation. Over three quarters of the variation can be predicted, with plasmi...
Source: Plasmid - January 11, 2020 Category: Biotechnology Source Type: research
ORF-based binarized structure network analysis of plasmids (OSNAp), a novel approach to core gene-independent plasmid phylogeny
ConclusionOSNAp is a novel holistic approach to assess relatedness of a population of plasmids in a given plasmid group based on nucleotide sequence data. It provides higher discrimination than pMLST, which may prove useful in tracing bacteria that harbor plasmids of shared origins. (Source: Plasmid)
Source: Plasmid - December 21, 2019 Category: Biotechnology Source Type: research
Editorial Board
Publication date: January 2020Source: Plasmid, Volume 107Author(s): (Source: Plasmid)
Source: Plasmid - December 20, 2019 Category: Biotechnology Source Type: research
A novel expression vector for Corynebacterium glutamicum with an auxotrophy complementation system
In this study, the novel Escherichia coli-C. glutamicum shuttle expression vector pLY-4, derived from the expression vector pXMJ19, was constructed. The constitutive vector pLY-4 contains a large multiple cloning site, the strong promoter tacM and two selective markers: the original chloramphenicol resistance gene cat is used for molecular cloning operations, and the auxotrophy complementation marker alr, which can be stably replicated in the auxotrophic host strain without antibiotic selection pressure, is used for industrial fermentation. Heterologous expression of the gapC gene using the vector pLY-4 in C. glutamicum fo...
Source: Plasmid - November 21, 2019 Category: Biotechnology Source Type: research
Editorial Board
Publication date: November 2019Source: Plasmid, Volume 106Author(s): (Source: Plasmid)
Source: Plasmid - November 12, 2019 Category: Biotechnology Source Type: research
The Tcp plasmids of Clostridium perfringens require the resP gene to ensure stable inheritance
Publication date: Available online 9 November 2019Source: PlasmidAuthor(s): Sarah Revitt-Mills, Carmen Lao, Marie Archambault, Dena Lyras, Julian I. Rood, Vicki AdamsAbstractMany of the disease-causing toxins of the pathogenic bacterium Clostridium perfringens are harboured on large, highly stable, conjugative plasmids. Previous work has established the requirement of a ParMRC-like partitioning system for plasmid maintenance, but little is known about other mechanisms used to ensure stable plasmid inheritance. The archetypal 47 kb Tcp plasmid, pCW3, encodes a gene, resP, whose putative product has sequence similarity to ...
Source: Plasmid - November 10, 2019 Category: Biotechnology Source Type: research
Corrigendum to “De novo synthesis of the complete genome of coxsackievirus A10 based on Golden Gate cloning combined with promoter reconstruction” [Plasmid 103 (2019) 17–24]
Publication date: Available online 9 November 2019Source: PlasmidAuthor(s): Meng Li, Jing Chen (Source: Plasmid)
Source: Plasmid - November 9, 2019 Category: Biotechnology Source Type: research
SGI0, a relative of Salmonella genomic islands SGI1 and SGI2, lacking a class 1 integron, found in Proteus mirabilis
Publication date: Available online 6 November 2019Source: PlasmidAuthor(s): Claire de Curraize, Eliane Siebor, Catherine Neuwirth, Ruth M. HallAbstractSeveral groups of integrative mobilizable elements (IMEs) have been found at the 3′-end of the chromosomal trmE gene, all harbouring a class 1 integron. Here, a new IME, Salmonella Genomic Island 0 (SGI0), was found in trmE in a French clinical Proteus mirabilis strain. SGI0 was characterized by the lack of class 1 integron. SGI0 is closely related to the backbones of SGI1 (97.59% nucleotide identity) and SGI2 (97.72% nucleotide identity). SGI0 harboured also the AcaCD bin...
Source: Plasmid - November 7, 2019 Category: Biotechnology Source Type: research
Plasmid pSfr64a and the symbiotic plasmid pSfr64b of Sinorhizobium fredii GR64 control each other's conjugative transfer through quorum-sensing elements
Publication date: Available online 2 November 2019Source: PlasmidAuthor(s): Laura Cervantes, Fabiola Miranda-Sánchez, Gonzalo Torres Tejerizo, David Romero, Susana BromAbstractRhizobia are nitrogen-fixing symbionts of plants. Their genomes frequently contain large plasmids, some of which are able to perform conjugative transfer. Plasmid pSfr64a from Sinorhizobium fredii GR64 is a conjugative plasmid, whose transfer is regulated by quorum sensing genes encoded by itself (traR64a, traI64a), in the symbiotic plasmid pSfr64b (traR64b, traI64b), and in the chromosome (ngrI). Also, transfer of pSfr64b requires quorum sensing el...
Source: Plasmid - November 3, 2019 Category: Biotechnology Source Type: research
Two novel transcriptional reporter systems for monitoring Helicobacter pylori stress responses
Publication date: November 2019Source: Plasmid, Volume 106Author(s): A.M. Belova, D.V. Basmanov, V.V. Babenko, O.V. Podgorny, T.V. Mitko, K.A. Prusakov, D.V. Klinov, V.N. LazarevAbstractHelicobacter pylori, a human pathogen linked to many stomach diseases, is well adapted to colonize aggressive gastric environments, and its virulence factors contribute this adaptation. Here, we report the construction of two novel H. pylori vectors, pSv2 and pSv4, carrying a reporter gene fused to the promoters of virulence factor genes for monitoring the response of single H. pylori cells to various stresses. H. pylori cryptic plasmids we...
Source: Plasmid - November 3, 2019 Category: Biotechnology Source Type: research
Synthetic promoter for efficient and muscle-specific expression of exogenous genes
Publication date: Available online 30 October 2019Source: PlasmidAuthor(s): Yili Liu, Yutong He, Yong Wang, Ming Liu, Mingfeng Jiang, Rong Gao, Gang WangAbstractSynthetic promoters (SPs) have many advantages over their natural counterparts, especially with regard to transcriptional activity and tissue specificity. Here, we report a new strategy to construct SPs for efficient and muscle-specific gene expression. First, 19 nucleic acid motifs classified to 3 kinds of transcriptional regulatory elements were rationally selected. A recombinant promoter library was constructed by randomly assembling these motifs. Second, the tr...
Source: Plasmid - October 31, 2019 Category: Biotechnology Source Type: research
Dissemination of blaKPC-2 in an NTEKPC by an IncX5 plasmid
This study reports the dissemination of a blaKPC-2-carrying NTEKPC among ST11/CG258 K. pneumoniae strains and ST1642 K. quasipneumoniae subsp. quasipneumoniae AMKP9 in an Amazonian hospital. The dissemination was due to pAMKP10, an ~48 kbp IncX5 plasmid carrying ΔISKpn6/blaKPC-2/ISKpn27 in a Tn1722-based unit. Although similar to NTEKPC-Ia from pKP048 described in China, a different transposase is present upstream of ISKpn27. Additionally, mutations were identified downstream of ISKpn27 but did not affect the blaKPC-2 promoter regions. pAMKP10 conjugated in vitro only from CG258 isolates. Since CG258 strains are generally...
Source: Plasmid - October 26, 2019 Category: Biotechnology Source Type: research
Editorial Board
Publication date: September 2019Source: Plasmid, Volume 105Author(s): (Source: Plasmid)
Source: Plasmid - October 26, 2019 Category: Biotechnology Source Type: research
