Deinbollia mosaic virus genome brief description

← Term 1

Last updated: 14-10-2016.

Main Information

Deinbollia mosaic virus belongs to ssDNA viruses; Geminiviridae; Begomovirus[0]. As it typical for Geminiviridae, Deinbollia mosaic virus is a plant virus consisting of two geminate particles with icosahedral symmetry[2] (Fig. 1). As it common among Begomovirus, it's genome is made up of two segments which are circular ssDNA molecules (each geminate particle contains only a single ssDNA molecule)[3]. Deinbollia mosaic virus's host is Deinbollia Borbonica, plant, growing in Tanzania (Fig. 2). Virus causes plant's mosaic disease [0].

Figure 1. Typical Geminiviridae morph. (Left) Cryo-electron microscopic reconstruction of maize streak virus (MSV). The bar represents 10 nm. (Right) Purified MSV particles stained with uranyl acetate. The bar represents 50 nm [1].

Figure 2. Deinbollia Borbonica[4].

Replication

Replication in Begomovirus proceeds in several steps[3]:

  1. Virus penetrates into the plant's cell.
  2. Uncoating, the viral ssDNA genome penetrates into the nucleus (Fig. 3).
  3. The ssDNA is converted into dsDNA with the participation of cellular factors.
  4. Bidirectional dsDNA transcription from the IR promoter produces viral mRNAs and translation of viral proteins.
  5. Replication is initiated by cleavage of the (+)strand by REP, and occurs by rolling circle producing ssDNA genomes.
  6. These newly synthesised ssDNA can either:
    • be converted to dsDNA and served as a template for transcription/replication;
    • be encapsidated by CP and form virions released from the cell by budding;
    • be transported outside the nucleus, to a neighbouring cell through plasmodesmata (cell-cell movement) with the help of viral movement proteins.
Figure 3. Viral penetration into host nucleus (pay attention to "ssDNA viruses")[5].

The shortest protein

Deinbollia mosaic virus has eight proteins in total (Table 1) and the shortest of them is AC4 protein (Insertion 1) which may act as a suppressor of RNA-mediated gene silencing, a mechanism of plant viral defence that limits the accumulation of viral RNAs[6].

Attribute Value
English virus name Deinbollia mosaic virus
Russian virus name Вирус мозаики Деинболлии
Amount of segments in full genome 2
Full genome length (bp) 5461
Amount of CDS (Coding DNA Sequence) 8
Amount of mature virus proteins 8

Table 1. Main Deinbollia mosaic virus genome parameters.

>>YP_009241414.1 AC4 [Deinbollia mosaic virus]
MPWFNSRANTTAQIRDSSTWNPQPGQHITIQTFRELNQAQMSSPISTRTATQPAGENIRSTADLLEEASR
ILTTWAQRP

Insertion 1. AC4 viral protein sequence in FASTA format.

References

[0] Virus-Host DB.
[1] Zhang et al. (2001). Virology, 279, 471–477 and courtesy of R. McKenna.
[2] Geminiviridae at ViralZone.
[3] Begomovirus at ViralZone.
[4] Deinbollia Borbonica picture.
[5] Viral penetration into host nucleus at ViralZone.
[6] AC4 protein at UniProt.

© Simon Galkin, 2016