Escherichia virus G4 is a
bacteriophage
A bacteriophage (), also known informally as a phage (), is a virus that infects and replicates within bacteria. The term is derived . Bacteriophages are composed of proteins that Capsid, encapsulate a DNA or RNA genome, and may have structu ...
that infects ''
E. coli
''Escherichia coli'' ( )Wells, J. C. (2000) Longman Pronunciation Dictionary. Harlow ngland Pearson Education Ltd. is a gram-negative, facultative anaerobic, rod-shaped, coliform bacterium of the genus ''Escherichia'' that is commonly foun ...
''.
First isolated in 1973, the phage was originally isolated from samples of raw sewage and has 5,577 nucleotides. Its isometric
capsid
A capsid is the protein shell of a virus, enclosing its genetic material. It consists of several oligomeric (repeating) structural subunits made of protein called protomers. The observable 3-dimensional morphological subunits, which may or m ...
contains a single-stranded circular
genome
A genome is all the genetic information of an organism. It consists of nucleotide sequences of DNA (or RNA in RNA viruses). The nuclear genome includes protein-coding genes and non-coding genes, other functional regions of the genome such as ...
of about 5.5
kbp. Phage G4 bears high genetic and structural similarity to the phage
ΦX174
The phi X 174 (or ΦX174) bacteriophage is a single-stranded DNA ( ssDNA) virus that infects ''Escherichia coli''. This virus was isolated in 1935 by Nicolas Bulgakov in Félix d'Hérelle's laboratory at the Pasteur Institute, from samples co ...
, though the two phage genomes are up to 39 percent different by sequence.
Synthetic G4
Synthetic G4 (syn-G4) has the appearance of an icosahedral protein shell and is 50 nm in diameter. has been synthesized through
Polymerase Chain Reaction (PCR) assembly of short
oligonucleotide
Oligonucleotides are short DNA or RNA molecules, oligomers, that have a wide range of applications in genetic testing, Recombinant DNA, research, and Forensic DNA, forensics. Commonly made in the laboratory by Oligonucleotide synthesis, solid-phase ...
s. The synthetic phage G4 genomes were effective in ''
E. coli
''Escherichia coli'' ( )Wells, J. C. (2000) Longman Pronunciation Dictionary. Harlow ngland Pearson Education Ltd. is a gram-negative, facultative anaerobic, rod-shaped, coliform bacterium of the genus ''Escherichia'' that is commonly foun ...
''.
Phage Therapy
Urinary Tract Infections (UTIs) are mainly caused by uropathogenic E. coli, and bacteriophage G4 can be used to treat it. The bacteriophage inject their DNA into the bacteria, releasing many new bacteriophages. This process has many benefits:
# The bacteriophage do not attack animal or human cells, only E. coli bacteria.
# The bacteriophage reproduce exponentially, so only a small amount is needed.
# After the bacteriophage have attached and killed all the bacteria, they disperse throughout the body and are harmless.
References
External links
UniProt TaxonomyNCBI TaxonomyNCBI Nucleotide (full genome)
{{Taxonbar, from=Q5380215
Microviridae