Bacteriophages of Borrelia burgdorferi are a biologically important but under-investigated feature of the Lyme disease-causing spirochete. No virulent borrelial viruses have been identified, but all B. burgdorferi isolates carry a prophage φBB1 as resident circular plasmids. Like its host, the φBB1 phage is quite distinctive and shares little sequence similarity with other known bacteriophages. We expressed φBB1 head morphogenesis proteins in Escherichia coli which resulted in assembly of homogeneous prolate procapsid structures and used cryo-electron microscopy to determine the three-dimensional structure of these particles. The φBB1 procapsids consist of 415 copies of the major capsid protein and an equal combined number of three homologous capsid decoration proteins that form trimeric knobs on the outside of the particle. One of the end vertices of the particle is occupied by a portal assembled from twelve copies of the portal protein. The φBB1 scaffolding protein is entirely α-helical and has an elongated shape with a small globular domain in the middle. Within the tubular section of the procapsid, the internal scaffold is built of stacked rings, each composed of 32 scaffolding protein molecules, which run in opposite directions from both caps with a heterogeneous part in the middle. Inside the portal-containing cap, the scaffold is organized asymmetrically with ten scaffolding protein molecules bound to the portal. The φBB1 procapsid structure provides better insight into the vast structural diversity of bacteriophages and presents clues of how elongated bacteriophage particles might be assembled.
- Klíčová slova
- capsid, cryo-EM, portal, scaffold, virus assembly,
- MeSH
- bakteriofágy * chemie genetika MeSH
- Borrelia * virologie MeSH
- elektronová kryomikroskopie MeSH
- kapsida * chemie MeSH
- sestavení viru MeSH
- virové plášťové proteiny metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- virové plášťové proteiny MeSH
Bacteriophages, or "phages" for short, are viruses that replicate in bacteria. The therapeutic and biotechnological potential of phages and their lytic enzymes is of interest for their ability to selectively destroy pathogenic bacteria, including antibiotic-resistant strains. Introduction of phage preparations into medicine, biotechnology, and food industry requires a thorough characterization of phage-host interaction on a molecular level. We employed Raman tweezers to analyze the phage-host interaction of Staphylococcus aureus strain FS159 with a virulent phage JK2 (=812K1/420) of the Myoviridae family and a temperate phage 80α of the Siphoviridae family. We analyzed the timeline of phage-induced molecular changes in infected host cells. We reliably detected the presence of replicating phages in bacterial cells within 5 min after infection. Our results lay the foundations for building a Raman-based diagnostic instrument capable of real-time, in vivo, in situ, nondestructive characterization of the phage-host relationship on the level of individual cells, which has the potential of importantly contributing to the development of phage therapy and enzybiotics.
The treatment of three patients suffering from chronic bacterial prostatitis who were qualified for an experimental phage therapy protocol managed at the Phage Therapy Unit in Wrocław is described. They had previously been treated unsuccessfully with long-term targeted antibiotics, autovaccines, and laser biostimulation. Rectal application of phage lysates targeted against Enterococcus faecalis cultured from the prostatic fluid gave encouraging results regarding bacterial eradication, abatement of clinical symptoms of prostatitis, and lack of early disease recurrence.
- MeSH
- bakteriofágy chemie fyziologie MeSH
- biologická terapie * MeSH
- dospělí MeSH
- Enterococcus faecalis izolace a purifikace virologie MeSH
- grampozitivní bakteriální infekce mikrobiologie terapie MeSH
- lidé MeSH
- prostatitida mikrobiologie terapie MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- mužské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- kazuistiky MeSH
An open reading frame encoding an 88 amino acid protein was present downstream of the previously characterized endolysin of Streptomyces aureofaciens phage micro1/6. Structural analysis of its sequence revealed features characteristic for holin. This open reading frame encoding the putative holin was amplified by polymerase chain reaction and cloned into the expression vector pET-21d(+). Synthesis of the holin-like protein resulted in bacterial cell death but not lysis. The holmicro1/6 gene was able to complement the defective lambda S allele in the nonsuppressing Escherichia coli HB101 strain to produce phage progeny, This fact suggests that the proteins encoded by both phage genes have analogous function, i.e. the streptomycete holin induces nonspecific lesions in the cytoplasmic membrane, through which the lambda endolysin gains an access to its substrate, the cell wall. The concomitant expression of both S. aureofaciens holmicro 1/6 and lambda endolysin in E. coli resulted in abrupt cell lysis. This result provided further evidence that the product of holmicro 1/6 gene is a holin.
- MeSH
- bakteriofágy chemie genetika metabolismus MeSH
- bakteriolýza MeSH
- endopeptidasy genetika metabolismus MeSH
- Escherichia coli genetika růst a vývoj metabolismus MeSH
- klonování DNA MeSH
- molekulární sekvence - údaje MeSH
- sekvence aminokyselin MeSH
- sekvence nukleotidů MeSH
- sekvenční analýza DNA MeSH
- Streptomyces aureofaciens virologie MeSH
- virové proteiny chemie genetika metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- endolysin MeSH Prohlížeč
- endopeptidasy MeSH
- virové proteiny MeSH
