scholarly journals Rebooting Synthetic Phage-Inducible Chromosomal Islands: One Method to Forge Them All

2020 ◽  
Vol 2020 ◽  
pp. 1-14 ◽  
Author(s):  
Rodrigo Ibarra-Chávez ◽  
Andreas F. Haag ◽  
Pedro Dorado-Morales ◽  
Iñigo Lasa ◽  
José R. Penadés

Phage-inducible chromosomal islands (PICIs) are a widespread family of mobile genetic elements, which have an important role in bacterial pathogenesis. These elements mobilize among bacterial species at extremely high frequencies, representing an attractive tool for the delivery of synthetic genes. However, tools for their genetic manipulation are limited and timing consuming. Here, we have adapted a synthetic biology approach for rapidly editing of PICIs in Saccharomyces cerevisiae based on their ability to excise and integrate into the bacterial chromosome of their cognate host species. As proof of concept, we engineered several PICIs from Staphylococcus aureus and Escherichia coli and validated this methodology for the study of the biology of these elements by generating multiple and simultaneous mutations in different PICI genes. For biotechnological purposes, we also synthetically constructed PICIs as Trojan horses to deliver different CRISPR-Cas9 systems designed to either cure plasmids or eliminate cells carrying the targeted genes. Our results demonstrate that the strategy developed here can be employed universally to study PICIs and enable new approaches for diagnosis and treatment of bacterial diseases.

Parasitology ◽  
1985 ◽  
Vol 90 (1) ◽  
pp. 57-66 ◽  
Author(s):  
Y. Schlein ◽  
I. Polacheck ◽  
B. Yuval

High incidence of mycoses were found in the guts and malpighian tubes of Phlebokomus papatasi from the Jordan Valley and P. tobbi from Zakinthos, Greece. Infections with several different bacteria were also found in the guts of female P. tobbi. Fungi cultured from guts of laboratory reared P. papatasi that had similar mycoses were identified as Aspergillus scierotiorum and Saccharomyces cerevisiae. Fungi-infected laboratory reared P. papatasi were refractory to artificial infections with a Leishmania major strain specific to them. The crop contents of P. papatasi, where sugar meals are stored, demonstrated antibacterial activity against the following bacterial species in culture: Escherichia coli, Staphylococcus aureus, Shigella sonnei, Streptococcus group A and Pseudomonas aeruginosa. It is postulated that the bacteria-free gut normal to sandflies is effected by the bacterial inhibitor present in the crop.


2021 ◽  
Author(s):  
Yuki Kanai ◽  
Saburo Tsuru ◽  
Chikara Furusawa

Operons are a hallmark of the genomic and regulatory architecture of prokaryotes. However, the mechanism by which two genes placed far apart gradually come close and form operons remains to be elucidated. Here, we propose a new model of the origin of operons: Mobile genetic elements called insertion sequences can facilitate the formation of operons by consecutive insertion-deletion-excision reactions. This mechanism barely leaves traces of insertion sequences and is difficult to detect in evolution in nature. We performed, to the best of our knowledge, the first experimental demonstration of operon formation, as a proof of concept. The insertion sequence IS3 and the insertion sequence excision enhancer are genes found in a broad range of bacterial species. We introduced these genes into insertion sequence-less Escherichia coli and found that, supporting our hypothesis, the activity of the two genes altered the expression of genes surrounding IS3, closed a 2.7 kilobase pair gap between a pair of genes, and formed new operons. This study shows how insertion sequences can facilitate the rapid formation of operons through locally increasing the structural mutation rates and highlights how coevolution with mobile elements may shape the organization of prokaryotic genomes and gene regulation.


2019 ◽  
Author(s):  
Thomas Siemon ◽  
Zhangqian Wang ◽  
Guangkai Bian ◽  
Tobias Seitz ◽  
Ziling Ye ◽  
...  

Herein, we report the semisynthetic production of the potent transient receptor potential canonical (TRPC) channel agonist (−)-englerin A (EA), using guaia-6,10(14)-diene as the starting material. Guaia-6,10(14)-diene was systematically engineered in Escherichia coli and Saccharomyces cerevisiae using the CRISPR/Cas9 system and produced with high titers. This provided us the opportunity to execute a concise chemical synthesis of EA and the two related guaianes (−)-oxyphyllol and (+)-orientalol E. The potentially scalable approach combines the advantages of synthetic biology and chemical synthesis and provides an efficient and economical method for producing EA as well as its analogs.


2019 ◽  
Author(s):  
Thomas Siemon ◽  
Zhangqian Wang ◽  
Guangkai Bian ◽  
Tobias Seitz ◽  
Ziling Ye ◽  
...  

Herein, we report the semisynthetic production of the potent transient receptor potential canonical (TRPC) channel agonist (−)-englerin A (EA), using guaia-6,10(14)-diene as the starting material. Guaia-6,10(14)-diene was systematically engineered in Escherichia coli and Saccharomyces cerevisiae using the CRISPR/Cas9 system and produced with high titers. This provided us the opportunity to execute a concise chemical synthesis of EA and the two related guaianes (−)-oxyphyllol and (+)-orientalol E. The potentially scalable approach combines the advantages of synthetic biology and chemical synthesis and provides an efficient and economical method for producing EA as well as its analogs.


Toxins ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 19 ◽  
Author(s):  
Maria B. Nowakowska ◽  
François P. Douillard ◽  
Miia Lindström

The botulinum neurotoxin (BoNT) has been extensively researched over the years in regard to its structure, mode of action, and applications. Nevertheless, the biological roles of four proteins encoded from a number of BoNT gene clusters, i.e., OrfX1-3 and P47, are unknown. Here, we investigated the diversity of orfX-p47 gene clusters using in silico analytical tools. We show that the orfX-p47 cluster was not only present in the genomes of BoNT-producing bacteria but also in a substantially wider range of bacterial species across the bacterial phylogenetic tree. Remarkably, the orfX-p47 cluster was consistently located in proximity to genes coding for various toxins, suggesting that OrfX1-3 and P47 may have a conserved function related to toxinogenesis and/or pathogenesis, regardless of the toxin produced by the bacterium. Our work also led to the identification of a putative novel BoNT-like toxin gene cluster in a Bacillus isolate. This gene cluster shares striking similarities to the BoNT cluster, encoding a bont/ntnh-like gene and orfX-p47, but also differs from it markedly, displaying additional genes putatively encoding the components of a polymorphic ABC toxin complex. These findings provide novel insights into the biological roles of OrfX1, OrfX2, OrfX3, and P47 in toxinogenesis and pathogenesis of BoNT-producing and non-producing bacteria.


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