Mimiviridae is a family of viruses. Amoeba and other protists serve as natural hosts. The family contains three subfamilies that contain nine genera.[, UCPMS ID: 1889607, PDF][ Fig. 4 and §Discussion: "Considering that tupanviruses comprise a sister group to amoebal mimiviruses..."] Viruses in this family belong to the nucleocytoplasmic large DNA virus clade (NCLDV), also referred to as giant viruses.
History
The first member of this family, Mimivirus, was discovered in 2003,
and the first complete genome sequence was published in 2004.
However, the mimivirus Cafeteria roenbergensis virus
was isolated and partially characterized in 1995,
although the host was misidentified at the time, and the virus was designated BV-PW1.
Taxonomy
The family contains the following subfamilies and genera (-
virinae denotes subfamily and -
virus denotes genus):
Structure
particles and its replication
]] Viruses in
Mimiviridae have icosahedral and round geometries, with between T=972 and T=1141, or T=1200 symmetry. The diameter is around 400 nm, with a length of 125 nm. Genomes are linear and non-segmented, around 1200kb in length. The genome has 911 open reading frames.
Life cycle
Replication follows the DNA strand displacement model. DNA-templated transcription is the method of transcription. Amoeba serve as the natural host.
Molecular biology
Three putative DNA base excision repair enzymes were characterized from Mimivirus.
[Lad SB, Upadhyay M, Thorat P, Nair D, Moseley GW, Srivastava S, Pradeepkumar PI, Kondabagil K. Biochemical Reconstitution of the Mimiviral Base Excision Repair Pathway. J Mol Biol. 2023 Sep 1;435(17):168188. doi: 10.1016/j.jmb.2023.168188. Epub 2023 Jun 26. PMID 37380013] The base excision repair (BER) pathway was experimentally reconstituted using the purified recombinant proteins uracil-DNA glycosylase (mvUDG),
AP endonuclease (mvAPE), and
DNA polymerase X protein (mvPolX).
[ When reconstituted in vitro mvUDG, mvAPE and mvPolX function cohesively to repair uracil-containing DNA predominantly by long patch base excision repair, and thus these processes likely participate in the BER pathway early in the Mimivirus life cycle.][
]
Clinical
Mimiviruses have been associated with pneumonia but their significance is currently unknown.
Mimivirus has also been implicated in rheumatoid arthritis.
See also
External links
