Single-Stranded Satellite DNAs
These satellites have a ssDNA genome that does not encode a satellite CP. The 682 nts DNA contains no ORF. Its replication is supported by geminiviruses in the genera Begomovirus and Curtovirus. See Dry, Krake, Rigden and Rezaian, 1997.
The satellite name is:
Tomato leaf curl virus satellite DNA
Double-Stranded Satellite RNAs
The only examples in this category are satellites found in association with viruses in the family Totiviridae. The dsRNAs range in size from 0.5 to 1.8 kbp and are encapsidated in helper virus coat protein; these particles often also contain a positive-sense single-stranded copy of the dsRNA. The presence of satellites in helper virus cultures can markedly affect the virulence of the helper virus infection. See Shelbourn, Day and Buck, 1988; Tai, Chang, Ip and Ong, 1995 and Wickner, 1996.
The satellite names are:
satellite of Saccharomyces cerevisiae M virus
satellite of Trichomonas vaginalis T1 virus
Satellite of Ustilago maydis killer M virus
Single-Stranded Satellite RNAs
These satellites have ssRNA genomes that do not encode a capsid protein. Particles containing satellite RNA are antigenically identical to those of the helper virus but can sometimes be distinguished by physical features such as sedimentation rates. Three different subgroups of these satellites are distinguished: Large satellite RNAs which are mRNA, small linear satellite RNAs and circular satellite RNAs.
Subgroup 1: Large Satellite RNAs
This category comprises satellites with genomes that are 0.8 to 1.5 kb in size and encode a non-structural protein that, at least in some cases, is essential for satellite RNA multiplication. Little sequence homology exists between the satellites and their helpers, some satellites can be exchanged among different helper viruses. These satellites rarely modify the disease induced in host plants by the helper virus. See Fritsch, Mayo and Hemmer, 1993; Hans and Pinck and Pinck, 1993; Hemmer, Meyer, Greif and Fritsch, 1987; Kigachi, Saito and Tamada, 1996; Kreiah, Cooper and Strunk, 1993; Lin, LeeLin, Lee and Hsu, 1996; Liu and Cooper, 1993 and Rubino, Burgyan, Grieco and Russo, 1990.
The satellite names are:
Arabis mosaic virus large satellite RNA
Bamboo mosaic virus satellite RNA
Chicory yellow mottle virus large satellite RNA
Grapevine Bulgarian latent virus satellite RNA
Grapevine fanleaf virus satellite RNA
Myrobalan latent ringspot virus satellite RNA
Strawberry latent ringspot virus satellite RNA
Tomato black ring virus satellite RNA (TBRV-G serotype satellite RNA)
Beet ringspot virus satellite RNA (formerly TBRV-S serotype satellite RNA)
Beet necrotic yellow vein virus satellite - like RNA5.
Subgroup 2: Small Linear Satellite RNAs
These satellites have genomes of less than 0.7 kb that do not encode functional proteins. No circular molecules are present in infected cells. Some satellites can attenuate the symptoms of helper virus infection, whereas other satellites can exacerbate the symptoms. See Celix, Rodriguez-Cerezo and Garcia-Arenal, 1997; Collmer and Howell, 1992; Dalmay and Rubino, 1995; Demler and de Zoeten, 1989; Francki, 1985; Gallitelli and Hull, 1985; Monis, Sopher and Jackson, 1992; Naidu, Collins and Ghabrial, 1991; Rubino, Tousignant, Steger and Kaper, 1990; Simon and Howell, 1986 and Skoric, Krajacic and Stefanac, 1997.
The satellite names are:
Cucumber mosaic virus satellite RNA (several types)
Cymbidium ringspot virus satellite RNA
Groundnut rosette virus satellite RNA
Panicum mosaic virus satellite RNA
Pea enation mosaic virus satellite RNA
Peanut stunt virus satellite RNA
Tomato bushy stunt virus satellite RNA (several types)
Turnip crinkle virus satellite RNA
Robinia mosaic virus satellite RNA
Tobacco necrosis virus small satellite RNA
Subgroup 3: Circular Satellites RNAs
These satellites have genomes that are about 350 nts long that occur as circular as well as linear molecules. Replication of some has been shown to involve self-cleavage of circular progeny molecules by an RNA-catalyzed reaction. See AbouHaidar and Paliwal, 1988; Davies, Haseloff and Symons, 1990; Etscheid, Tousignant and Kaper, 1995; Passmore and Bruening, 1993; Rasochova and Miller, 1996; Rubino, Tousignant, Steger and Kaper, 1990; Sehgal, AbouHaidar, Gellatly, Ivanov and Thottapilly, 1993 and Symons, 1997.
The satellite names are:
Arabis mosaic virus small satellite RNA
Cereal yellow dwarf virus-RPV satellite RNA
Chicory yellow mottle virus satellite RNA
Lucerne transient streak virus satellite RNA
Solanum nodiflorum mottle virus satellite RNA
Subterranean clover mottle virus satellite RNA (2 types)
Tobacco ringspot virus satellite RNA
Velvet tobacco mottle virus satellite RNA
Rice yellow mottle virus satellite
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