A. Cordonnier et al., ISOLATION OF NOVEL HUMAN ENDOGENOUS RETROVIRUS-LIKE ELEMENTS WITH FOAMY VIRUS-RELATED POL SEQUENCE, Journal of virology, 69(9), 1995, pp. 5890-5897
A new class of reverse transcriptase coding sequences was detected in
reverse transcribed RNAs from human placenta by polymerase chain ampli
fication with primers in highly conserved regions of the pol gene of m
ammalian retroviruses and retrotransposons. Using one of these novel s
equences as a probe to screen a human genomic library, we isolated ret
rovirus-like elements bordered by long terminal repeats and having a p
otential leucine tRNA primer-binding site. Determination of the comple
te nucleotide sequence (6,591 bp) of one of these elements, termed HER
V-L (for human endogenous retrovirus with leucine tRNA primer), reveal
ed domains of amino acid similarities to retroviral reverse transcript
ase and integrase proteins. In addition, a region with homologies to d
UTPase proteins was found unexpectedly downstream from the integrase d
omain. Amino acid sequence and phylogenetic analyses indicate that the
HERV-L pol gene is related to that of foam;g retroviruses. HERV-L-rel
ated sequences are detected in several mammalian species and have expa
nded in primate and mouse genomes up to 100 to 200 copies.