| Modification Notes |
Mammalian LINE-1 (L1) elements belong to the superfamily of autonomously replicating retrotransposable elements that lack the long terminal repeated (LTR) sequences typical of retroviruses and retroviral-like retrotransposons. The non-LTR superfamily is ubiquitous in nature and constitutes 20% or more of some mammalian genomes, and about 5% of the human genome. Therefore, Line-1 elements presumably have had a profound, perhaps defining, effect on the evolution, structure and function of mammalian genomes. Line-1 elements contain regulatory signals and encode two proteins: an RNA-binding protein and an integrase-replicase, as the retrovirus harbors both endonuclease and reverse transcriptase capabilities. |