imported>Lcovelli at 13:48, 15 March 2010

2010-03-15T13:48:41Z

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{{Element
|genbank=[http://www.ncbi.nlm.nih.gov/nuccore/1399881 1399881]
|type=
|genus= Cavemovirus
|subfamily= Class 3
|family= Caulimoviridae
|group= LTR retroelements
|description=''Cassava vein mosaic virus'' (CsVMV) is a plant pararetrovirus found primarily in Brazil, where it infecting cassava plants (''Manihot'' spp.) produces mild symptoms characterized by chlorosis followed by mosaic veins, leaf distortion and epinasty of the young leaves ([[Literature:10456|Calvert ''et al.'' 1995]]; [[Literature:100606|de Kochko ''et al.'' 1998]]).
CsVMV is the type species of ''Cavemovirus'' genus (for more details see [http://www.ncbi.nlm.nih.gov/ICTVdb/ICTVdB/00.015.0.03.001.htm ICTVdb]) of [[Caulimoviridae|''Caulimoviridae'']] plant virus family and together to the ''Tobacco vein clearing virus'' (TVCV) are the two species of Class 3 in the phylogenetic analysis performed by [[Literature:100596|Llorens ''et al'' 2009]].

CsVMV has isometric particles of 50-60 nm in diameter ([[Literature:100625|Kitajima and Costa, 1966]]) composed of a genomic 8159 bp dsDNA ([[Literature:100606|de Kochko ''et al.'' 1998]]). The genome of CsVMV is organized in five ORFs ([[Literature:100606|de Kochko ''et al.'' 1998]]) and not in six as previously reported ([[Literature:10456|Calvert ''et al.'' 1995]], [http://www.ncbi.nlm.nih.gov/entrez/viewer.fcgi?db=nucleotide&val=665931 U20341]). It is due to the presence of two Adenine (AA) (instead of only one A) at position 6817-18 that induce a frameshift such that previous described ORF IV and V become only one ORF (ORF IV) ([[Literature:100606|de Kochko ''et al.'' 1998]]). The ORF I contains both the COAT (gag) and movement protein (MOV) domains in the same order of the other ''Cavemovirus'' species TVCV ([[Literature:100606|de Kochko ''et al.'' 1998]]; [[Literature:10456|Calvert ''et al.'' 1995]]; [[Literature:100607|Lockhart ''et al.'' 2000]]). The consensus RNA-binding sequence associated to the putative COAT-''gag'' region, like that of other plant pararetrovirus, is larger than the related retroelement consensus RNA-binding sequence (C-X2-C-X4-H-X4-C) because it includes an additional cysteine (Cys) at the -2 position (C-X-C-X2-C-X4-H-X4-C ) ([[Literature:100605|Hull 1996]]; [[Literature:8054|Bouhida ''et al.'' 1993]]). ORF III and IV display respectively the pol-polyprotein domain organization (protease, reverse transcriptase and RNaseH) and the transactivator region (TAV) typical of the other caulimoviruses. ORF II (between ''Gag-MOV'' and ''Pol'' genes) and ORF V (downstream of the intergenic region ) do not encode for any described protein, even if the ORF V-oligopeptide could have a putative role in the transcription regulation ([[Literature:100606|de Kochko ''et al.'' 1998]]). Interestingly, our analyses have revealed the presence of a second protease-like domain downstream to the MOV region (C-terminus of ORF I) that shows sequence similarity to the conventional Pol-protease domain. A similar feature has been also observed in the genome of the two soymoviruses - ''Peanut chlorotic streak virus'' (PCSV) and ''Soybean chlorotic mottle virus'' (SbCMV ) - and of the tungrovirus ''Rice tungro bacilliform virus'' (RTBV), but it is not clear if these sequences are a functionally active proteases additional to those found in the ''Pol'' genes.

CsVMV can be transmitted by mechanical inoculation, as well as by stem cuttings that is used as reproductive material in the vegetative propagation ([[Literature:10456|Calvert ''et al.'' 1995]]).
|structure=CsVMV2.png
|host=Manihot esculenta
|hostpic=Manihot_esculenta.jpg
|literature=
|picowner=[http://www.biotechvana.com Image, Laura Covelli, Copyright, GyDB, Biotech Vana]
}}
[[Category:Element]]

Element:CSVMV - Revision history

imported>Lcovelli at 13:48, 15 March 2010