Human Endogenous Retrovirus type E (HERV-E) is a simple retrovirus (Steele et al. 1984; Repaske et al. 1985) that belongs to the genus Gammaretrovirus. Morphologically, HERV-E is consistent with mammalian C-type retroviruses, and its genomic structure is 8.8 Kb in size including LTRs of 495 and 497 nt, respectively. The internal region of this retrovirus displays a Primer Binding Site (PBS) complementary to a tRNAGlu, Open Reading Frames (ORFs) for gag-pol (the RNase H ORF displays a frameshifting +1 into +3 not depicted in the figure below) and env genes characteristic of retroviruses , and also a Polypurine Tract (PPT) adjacent to the 3´LTR (Repaske et al. 1985).
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:
||DU or DUT=dUTPase
||TAV or IBMP=transactivator/viroplasmin or inclusion body matrix protein
||PBS=primer binding site
||ATF=aphid transmission factor
||VAP=virion associated protein