Glossary Downstream A region of DNA at and near a terminus of transcription.
Long terminal repeats (LTRs) are identical DNA sequences (several hundred nucleotides in length) found at the ends of transposons and retrovirus-derived DNA. LTRs contain inverted repeats and are thought to play an essential role in the integration of the transposon or provirus into the host DNA. In
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Upstream A region of DNA at and near an origin of transcription.
proviruses, the upstream LTR acts as a promoter and enhancer and the downstream LTR as a polyadenylation site.
See also: Provirus; Retroviruses; Transposable Elements.
Brenner’s Encyclopedia of Genetics, 2nd edition, Volume 4