A study was carried out on the influence of point mutations of the functional amino acid residues on the secondary and ternary structure of bacteriophage T7 RNA polymerase as well as on the activity of the enzyme. A change in residue 631 is accompanied by significant changes in secondary structure (alpha-->beta transition). The substitution Lys-172 Leu changes both the secondary and ternary structures whereas the deletion of residues 172-173 does not lead to such changes. Changes in residues 631-632 do not affect the ability of the enzyme to bind the promoter and/or the synthesis of a full-length transcript but disturbs phosphodiester bond formation.
Download full-text PDF |
Source |
---|
Nucleic Acids Res
January 2025
Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China.
Achieving targeted hypermutation of specific genomic sequences without affecting other regions remains a key challenge in continuous evolution. To address this, we evolved a T7 RNA polymerase (RNAP) mutant that synthesizes single-stranded DNA (ssDNA) instead of RNA in vivo, while still exclusively recognizing the T7 promoter. By increasing the error rate of the T7 RNAP mutant, it generates mutated ssDNA that recombines with homologous sequences in the genome, leading to targeted genomic hypermutation.
View Article and Find Full Text PDFActa Naturae
January 2024
Lomonosov Moscow State University, Faculty of Biology, Moscow, 119234 Russian Federation.
Analytical electron microscopy techniques, including energy-dispersive X-ray spectroscopy (EDX) and electron energy-loss spectroscopy (EELS), are employed in materials science and biology to visualize and chemically map diverse elements. This review presents cases of successful identification of nucleic acids in cells and in DNA- and RNA-containing viruses that use the chemical element phosphorus as a marker.
View Article and Find Full Text PDFMethods Enzymol
January 2025
Area of Bioscience and Biotechnology, School of Materials Science, Japan Advanced Institute of Science and Technology, Asahidai, Nomicity, Ishikawa, Japan. Electronic address:
Site-directed RNA editing (SDRE) holds significant promise for treating genetic disorders resulting from point mutations. Gene therapy, for common genetic illnesses is becoming more popular and, although viable treatments for genetic disorders are scarce, stop codon mutation-related conditions may benefit from gene editing. Effective SDRE generally depends on introducing many guideRNA molecules relative to the target gene; however, large ratios cannot be achieved in the context of gene therapy applications.
View Article and Find Full Text PDFbioRxiv
January 2025
Institute for Systems Biology, Seattle, WA, USA.
Success of phage therapies is limited by bacterial defenses against phages. While a large variety of anti-phage defense mechanisms has been characterized, how expression of these systems is distributed across individual cells and how their combined activities translate into protection from phages has not been studied. Using bacterial single-cell RNA sequencing, we profiled the transcriptomes of ~50,000 cells from cultures of a human pathobiont, , infected with a lytic bacteriophage.
View Article and Find Full Text PDFAppl Microbiol Biotechnol
January 2025
Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224, Warsaw, Poland.
Bacteriophage infections in bacterial cultures pose a significant challenge to industrial bioprocesses, necessitating the development of innovative antiphage solutions. This study explores the antiphage potential of indigo carmine (IC), a common FDA-approved food additive. IC demonstrated selective inactivation of DNA phages (P001, T4, T1, T7, λ) with the EC values ranging from 0.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!