Bidensovirus

Bidensovirus
Virus classification
(unranked):	Virus
Realm :	Monodnaviria
Kingdom:	Shotokuvirae
Phylum:	Cossaviricota
Class:	Mouviricetes
Order:	Polivirales
Family:	Bidnaviridae
Genus:	Bidensovirus
Species
	Bombyx mori bidensovirus

Bidensovirus is a genus of single stranded DNA viruses that infect invertebrates. The species in this genus were originally classified in the family Parvoviridae (subfamily Densovirinae ) but were moved to a new genus because of significant differences in the genomes. ^[1]

Taxonomy [ edit ]

There is one species in this genus currently recognised: Bombyx mori bidensovirus .

Host [ edit ]

As the name suggests this virus infects Bombyx mori , the silkworm. ^[2]

Virology [ edit ]

The virions are icosahedral , non enveloped and ~25 nanometers in diameter. They contain two structural proteins .

The genome is bipartite, unique among ssDNA viruses, with two linear segments of ~6 and 6.5 kilobases (kb). These segments and the complementary strands are that are packaged separately giving rise to 4 different types of full particles.

Both segments have an ambisense organization, coding for a structural protein in one sense and the non-structural proteins on the complementary strand.

DNA1 (also known as VD1) ? the larger segment of 6.5 kb ? encodes the capsid protein VP1 (128 kDa ? kilodaltons) on one strand and three non-structural proteins ? NS1 of 14 kDa, NS2 of 37 kDa and NS3 of 55 kDa ? on the complementary strand.

DNA2 (also known as VD2) ? the smaller segment of 6 kb ? encodes the capsid protein VP2 (133 kDa) on one strand and the non-structural protein NS4 (27 kDa) on the complementary strand.

The open reading frame 4 (VD1-ORF4) is 3318 nucleotides (bases) in length and encodes a predicted ( 3318/3 ? 1 = ) 1105 amino acid protein which has a conserved DNA polymerase motif. It appears to encode at least 2 other proteins including one of ~53 kDa that forms part of the virion. ^[3]

Evolution [ edit ]

Comprehensive analysis of bidnavirus genes has shown that these viruses have evolved from a parvovirus ancestor from which they inherit a jelly-roll capsid protein and a superfamily 3 helicase . ^[4] It has been further suggested that the key event that led to the separation of the bidnaviruses from parvoviruses was the acquisition of the PolB gene. A likely scenario has been proposed under which the ancestral parvovirus genome was integrated into a large virus-derived DNA transposon of the Polinton /Maverick family (polintoviruses) ^[5] resulting in the acquisition of the polintovirus PolB gene along with terminal inverted repeats. Bidnavirus genes for a minor structural protein (putative receptor-binding protein) and a potential novel antiviral defense modulator were derived from dsRNA viruses ( Reoviridae ) and dsDNA viruses ( Baculoviridae ), respectively. ^[4]

References [ edit ]

^ Virus Taxonomy: Ninth Report of the International Committee on Taxonomy of Viruses (2011) ISBN 978-0123846846
^ "Bidensovirus ~ ViralZone page" .
^ Li, Guohui; Hu, Zhaoyang; Guo, Xuli; Li, Guangtian; Tang, Qi; Wang, Peng; Chen, Keping; Yao, Qin (June 2013). "Li G, Hu Z, Guo X, Li G, Tang Q, Wang P, Chen K, Yao Q Identification of Bombyx mori Bidensovirus VD1-ORF4 Reveals a Novel Protein Associated with Viral Structural Component. Curr Microbiol 66, 527?534 (2013)" . Current Microbiology . 66 (6): 527?534. doi : 10.1007/s00284-013-0306-9 . PMID 23328902 . S2CID 15920465 .
^ ^a ^b Krupovic M, Koonin EV (2014). "Evolution of eukaryotic single-stranded DNA viruses of the Bidnaviridae family from genes of four other groups of widely different viruses" . Sci Rep . 4 : 5347. doi : 10.1038/srep05347 . PMC 4061559 . PMID 24939392 .
^ Krupovic M, Bamford DH, Koonin EV (2014). "Conservation of major and minor jelly-roll capsid proteins in Polinton (Maverick) transposons suggests that they are bona fide viruses" . Biol Direct . 9 (1): 6. doi : 10.1186/1745-6150-9-6 . PMC 4028283 . PMID 24773695 .

External links [ edit ]

Bidensovirus ~ ViralZone page . The top image erraneously shows a monopartite genome, text and genome map are right (March 30, 2021).

[ICTV2011-1] Virus Taxonomy: Ninth Report of the International Committee on Taxonomy of Viruses (2011) ISBN 978-0123846846

[ViralZone-2] "Bidensovirus ~ ViralZone page" .

[Li-2013-3] Li, Guohui; Hu, Zhaoyang; Guo, Xuli; Li, Guangtian; Tang, Qi; Wang, Peng; Chen, Keping; Yao, Qin (June 2013). "Li G, Hu Z, Guo X, Li G, Tang Q, Wang P, Chen K, Yao Q Identification of Bombyx mori Bidensovirus VD1-ORF4 Reveals a Novel Protein Associated with Viral Structural Component. Curr Microbiol 66, 527?534 (2013)" . Current Microbiology . 66 (6): 527?534. doi : 10.1007/s00284-013-0306-9 . PMID 23328902 . S2CID 15920465 .

[Bidna-4] Krupovic M, Koonin EV (2014). "Evolution of eukaryotic single-stranded DNA viruses of the Bidnaviridae family from genes of four other groups of widely different viruses" . Sci Rep . 4 : 5347. doi : 10.1038/srep05347 . PMC 4061559 . PMID 24939392 .

[5] Krupovic M, Bamford DH, Koonin EV (2014). "Conservation of major and minor jelly-roll capsid proteins in Polinton (Maverick) transposons suggests that they are bona fide viruses" . Biol Direct . 9 (1): 6. doi : 10.1186/1745-6150-9-6 . PMC 4028283 . PMID 24773695 .

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