Element:EFV

Description Equine foamy virus (EFV) is a foamy retrovirus originally isolated from equine species. EFV belongs to genus Spumaretrovirus within Retroviridae family (International Committee on the Taxonomy of Viruses -ICTV- Fauquet et al. 2005) and according to Llorens et al. (2009) is located within Class 3 of the Retroviridae family. Similar to other foamy virus, EFV exhibits a highly characteristic ultrastructure and induces syncytium formation and subsequent cell lysis on a large number of cell lines (Tobaly-Tapiero et al. 2000). The genomic structure of EFV is 12.035 Kb in size including LTRs of 1.449 bp (Tobaly-Tapiero et al. 2000). The internal region of this retrovirus displays a Primer Binding Site (PBS) complementary to a tRNALys, three Open Reading Frames (ORFs) for gag, pol and env genes characteristic of retroviruses, two 3´accessory genes, and a Polypurine Tract (PPT) adjacent to the 3´LTR (Tobaly-Tapiero et al. 2000). The predicted Gag protein of EFV consists of 559 amino acids; the ORF of the pol gene -which harbors the protease, RT, RNase H and integrase domains- begins at position 3157 and consists of 1154 residues. The env gene encodes a predicted 987-residue and downstream to this ORF are located the two accessory genes, Tas-1 (ORF 1) and Bel-2 (Tobaly-Tapiero et al. 2000). The first one, the Tas-1 ORF (the spumaretroviruses transactivator, also called Bel 1) transactivates viral gene expression by direct binding to the viral DNA on specific sequences in the long terminal repeat (LTR) and in an internal promoter (IP) (Tobaly-Tapiero et al. 2000; Lecellier et al. 2002). Structure Figure not to scale. If present, long terminal repeats (LTRs) have been highlighted in blue. Amino acid motifs noted with lines indicate the conserved residues in each protein domain, abbreviations below mean: MA=matrix PR=protease DU or DUT=dUTPase TM=transmembrane TAV or IBMP=transactivator/viroplasmin or inclusion body matrix protein CA=capsid RT=reverse transcriptase INT=Integrase CHR=chromodomain NC=nucleocapsid RH=RNaseH SU=surface MOV=movement protein PPT=polypurine tract PBS=primer binding site ATF=aphid transmission factor VAP=virion associated protein Related literature Retroviruses. (Coffin, Hugges and Varmus 1997) Mobile DNA II. (Craig et al. 2002)

Genbank accession: 9634977 Clade: Undetermined Cluster or genus: Spumaretrovirus Branch or class: Class 3 Family: Retroviridae System: LTR retroelements Host: Explore the Tree Life Project Equidae sp. Image, Daniela Bezemer, Copyright, GyDB, Biotech Vana Browse all elements