SINEs. Bottom: proposed structure of L1 RNA-protein (RNP) complexes. ORF1 proteins form trimers, exhibiting RNA binding and nucleic acid chaperone activity.<unk> s (LINEs) (also known as<unk><unk>  nucleotide<unk> s or<unk><unk><unk> s) are a group of non-LTR <unk>  terminal repeat) retrotransposons that are widespread in the genome of many eukaryotes. They make up around 21.1% of the human genome. LINEs make up a family of transposons, where each LINE is about 7,000 base pairs<unk> . LINEs are transcribed into mRNA and translated into protein that acts as a reverse transcriptase. The reverse transcriptase makes a DNA copy of the LINE RNA that can be integrated into the genome at a new site. The only abundant LINE in humans is LINE1. The human genome contains an estimated 100,000 truncated and 4,000 full-length LINE-1<unk> s. Due to the accumulation of random mutations, the sequence of many LINEs has degenerated to the extent that they are no<unk> er transcribed or translated. Comparisons of LINE DNA sequences can be used to date transposon insertion in the genome.
Long interspersed nuclear element
TRNA 
CccDNA
Gene
Replicon 
Cis-regulatory element
Insertion sequence
Exosome 