Figure 1
From: Parasitism and the retrotransposon life cycle in plants: a hitchhiker's guide to the genome
Theoretical life cycle of LTR retrotransposons. (a) Transcription of the mRNA, starting from the 5′ R region to the 3′ R region. (b) Translation and protein synthesis of active elements in GAG and POL; POL is further internally cleaved by AP in AP, RT-RNAseH and IN. (c) Dimerization of RNA before or during packaging, using a ‘kissing-loop’ mechanism based on DIS recognition (see text). (d) Packaging of RNA and start of reverse transcription. The GAGs polymerize to form the VLP, in which the reverse transcription is performed by the dual protein RT-RNaseH. This allows the synthesis of the first strand of the cDNA using the packaged RNA as matrix. (e) Degradation of the RNA matrix and initiation of synthesis of the second strand of the cDNA. (f) Completion of the double-stranded cDNA synthesis and linkage of the IN to the LTRs. (g) Double-stranded break and integration of the newly synthesized copy in a new genomic location.
