Publications by authors named "Paul R Jaschke"

Article Synopsis
  • - Multidrug-resistant infections are rising globally, prompting interest in phage therapy as a potential solution, which utilizes naturally occurring viruses that infect bacteria.
  • - Researchers developed a biocontained phage system using a technique called conditional replication with amber stop codon suppression to address safety concerns related to engineered phages.
  • - This new system showed that modified phages could effectively infect specific host cells while preventing uncontrolled replication, suggesting a safe method for using engineered phages in healthcare settings.
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Bacteriophage ϕX174 is a small icosahedral virus of the Microviridae with a rapid replication cycle. Previously, we found that in ϕX174 infections of Escherichia coli, the most highly upregulated host proteins are two small heat shock proteins, IbpA and IbpB, belonging to the HSP20 family, which is a universally conserved group of stress-induced molecular chaperones that prevent irreversible aggregation of proteins. Heat shock proteins were found to protect against ϕX174 lysis, but IbpA/B have not been studied.

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Antimicrobial resistance is an escalating threat with few new therapeutic options in the pipeline. Urinary tract infections (UTIs) are one of the most prevalent bacterial infections globally and are prone to becoming recurrent and antibiotic resistant. We discovered and characterized six novel Autographiviridae and Guernseyvirinae bacterial viruses (phage) against uropathogenic Escherichia coli (UPEC), a leading cause of UTIs.

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Recent advances in genomic refactoring have been hindered by the ever-present complication of internal or cryptic transcriptional regulation. Typical approaches to these features have been to randomize or perform mass alterations to the gene sequences thought to contain the regulatory motifs; however, this approach can cause problems by altering translational speeds, introducing long distance DNA-DNA interaction effects, and inducing RNA toxicity. Previously, we developed a rational design approach named COdon Restrained Promoter SilEncing (CORPSE) which takes externally identified promoter sequences and uses position-specific scoring matrices as proxy promoter strengths to make minimal changes to promoter sequences to disable their activity.

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Background: Viruses play important roles in modulating microbial communities and influencing global biogeochemistry. There is now growing interest in characterising their ecological roles across diverse biomes. However, little is known about viral ecology in low-nutrient, chemotrophic-based environments.

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With the global increase of infections caused by antibiotic-resistant bacterial strains, there is an urgent need for new methods of tackling the issue. Genomic analysis of bacterial strains can help to understand their virulence and antibiotic resistance profile. Bioinformatic skills are in great demand across the biological sciences.

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Future applications of synthetic biology will rely on deploying engineered cells outside of lab environments for long periods of time. Currently, a significant roadblock to this application is the potential for deactivating mutations in engineered genes. A recently developed method to protect engineered coding sequences from mutation is called Constraining Adaptive Mutations using Engineered Overlapping Sequences (CAMEOS).

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Future applications of synthetic biology will require refactored genetic sequences devoid of internal regulatory elements within coding sequences. These regulatory elements include cryptic and intragenic promoters, which may constitute up to a third of the predicted promoters. The promoter activity is dependent on the structural interaction of core bases with a σ factor.

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Modern genome-scale methods that identify new genes, such as proteogenomics and ribosome profiling, have revealed, to the surprise of many, that overlap in genes, open reading frames and even coding sequences is widespread and functionally integrated into prokaryotic, eukaryotic and viral genomes. In parallel, the constraints that overlapping regions place on genome sequences and their evolution can be harnessed in bioengineering to build more robust synthetic strains and constructs. With a focus on overlapping protein-coding and RNA-coding genes, this Review examines their discovery, topology and biogenesis in the context of their genome biology.

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Bacteriophage plaque size measurement is essential for phage characterisation, but manual size estimation requires a considerable amount of time and effort. In order to ease the work of phage researchers, we have developed an automated command-line application called Plaque Size Tool (PST) that can detect plaques of different morphology on the images of Petri dishes and measure plaque area and diameter. Plaque size measurements using PST showed no difference to those obtained with manual plaque size measurement in Fiji, indicating future results using PST are backwards compatible with prior measurements in the literature.

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Measuring host-bacteriophage dynamics is an important approach to understanding bacterial survival functions and responses to infection. The model bacteriophage φX174 is endemic to the human gut and has been studied for over 70 years, but the host response to infection has never been investigated in detail. To address this gap in our understanding of this important interaction within our microbiome, we have measured host C proteomic and transcriptomic response to φX174 infection.

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Sequence overlap between two genes is common across all genomes, with viruses having high proportions of these gene overlaps. Genome modularization and refactoring is the process of disrupting natural gene overlaps to separate coding sequences to enable their individual manipulation. The biological function and fitness effects of gene overlaps are not fully understood, and their effects on gene cluster and genome-level refactoring are unknown.

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Bacteriophage ϕX174 is a model virus for studies across the fields of structural biology, genetics, gut microbiomics, and synthetic biology, but did not have a high-resolution transcriptome until this work. In this study we used next-generation sequencing to measure the RNA produced from ϕX174 while infecting its host E. coli C.

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Resistance to antibiotics is an escalating global crisis, presenting a major health, social, and economic burden. An underexplored alternative to antibiotic treatment is phage therapy whereby bacteriophages are used to infect and kill pathogenic multidrug-resistant (MDR) bacteria. A primary challenge is the highly specific infectivity range of phages that can limit their ability to infect across different bacterial strains.

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We develop a method for completing the genetics of natural living systems by which the absence of expected future discoveries can be established. We demonstrate the method using bacteriophage øX174, the first DNA genome to be sequenced. Like many well-studied natural organisms, closely related genome sequences are available-23 genomes related to øX174.

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The ability to separate, identify, and quantify proteins from complex mixtures are key foundational methods across biochemistry teaching and research. In particular, enzyme-linked immunosorbent assay (ELISA) is an important technique that is used to measure antigen concentrations in both industry and academia. There are four categories of ELISA, direct, indirect, competitive, and sandwich, each with their own applications.

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Using engineered initiator tRNA for precise control of protein translation within cells has great promise within future orthogonal translation systems to decouple housekeeping protein metabolism from that of engineered genetic systems. Previously, E. coli strain C321.

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Our understanding of translation underpins our capacity to engineer living systems. The canonical start codon (AUG) and a few near-cognates (GUG, UUG) are considered as the 'start codons' for translation initiation in Escherichia coli. Translation is typically not thought to initiate from the 61 remaining codons.

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Wet Lab Accelerator (WLA) is a cloud-based tool that allows a scientist to conduct biology via robotic control without the need for any programming knowledge. A drag and drop interface provides a convenient and user-friendly method of generating biological protocols. Graphically developed protocols are turned into programmatic instruction lists required to conduct experiments at the cloud laboratory Transcriptic.

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The 5386 nucleotide bacteriophage øX174 genome has a complicated architecture that encodes 11 gene products via overlapping protein coding sequences spanning multiple reading frames. We designed a 6302 nucleotide synthetic surrogate, øX174.1, that fully separates all primary phage protein coding sequences along with cognate translation control elements.

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The α-proteobacterium Rhodobacter sphaeroides is an exemplary model organism for the creation and study of novel protein expression systems, especially membrane protein complexes that harvest light energy to yield electrical energy. Advantages of this organism include a sequenced genome, tools for genetic engineering, a well-characterized metabolism, and a large membrane surface area when grown under hypoxic or anoxic conditions. This chapter provides a framework for the utilization of R.

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Heme and bacteriochlorophyll a (BChl) biosyntheses share the same pathway to protoporphyrin IX, which then branches as follows. Fe(2+) chelation into the macrocycle by ferrochelatase results in heme formation, and Mg(2+) addition by Mg-chelatase commits the porphyrin to BChl synthesis. It was recently discovered that a bchD (Mg-chelatase) mutant of Rhodobacter sphaeroides produces an alternative BChl in which Mg(2+) is substituted by Zn(2+).

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A procedure for modification of the valve stem of a 40 K French pressure cell is described. The modification should be done by a machinist and requires a metalworking lathe. After modification of the valve stem, a torlon 4203 plastic ball is used between the valve stem and valve seat to control the pressure within the cell.

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The cofactor composition and electron-transfer kinetics of the reaction center (RC) from a magnesium chelatase (bchD) mutant of Rhodobacter sphaeroides were characterized. In this RC, the special pair (P) and accessory (B) bacteriochlorophyll (BChl) -binding sites contain Zn-BChl rather than BChl a. Spectroscopic measurements reveal that Zn-BChl also occupies the H sites that are normally occupied by bacteriopheophytin in wild type, and at least 1 of these Zn-BChl molecules is involved in electron transfer in intact Zn-RCs with an efficiency of >95% of the wild-type RC.

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Rhodobacter capsulatus contains lhaA and pucC genes that have been implicated in light-harvesting complex 1 and 2 (LH1 and LH2) assembly. The proteins encoded by these genes, and homologues in other photosynthetic organisms, have been classified as the bacteriochlorophyll delivery (BCD) family of the major facilitator superfamily. A new BCD family phylogenetic tree reveals that several PucC, LhaA and Orf428-related sequences each form separate clusters, while plant and cyanobacterial homologues cluster more distantly.

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