Capsid protein (CA) is the structural component of the virus-like particle (VLP), forming the shell that encapsulates the retrotransposons dimeric RNA genome. The particles are assembled from trimer-clustered units and there are holes in the capsid shells that allow for the diffusion of macromolecules. CA has also nucleocapsid-like chaperone activity, promoting primer tRNA(i)-Met annealing to the multipartite primer-binding site (PBS), dimerization of Ty1 RNA and initiation of reverse transcription (By similarity). Homotrimer. The Gag-Pol polyprotein is generated by a +1 ribosomal frameshift. The ratio of Gag:Gag-Pol varies between 20:1 and 5:1 (By similarity). Ty1-PR1 is a highly expressed element. Induced under amino acid starvation conditions by GCN4. The C-terminal RNA-binding region of CA is sufficient for all its nucleocapsid-like chaperone activities. Retrotransposons are mobile genetic entities that are able to replicate via an RNA intermediate and a reverse transcription step. In contrast to retroviruses, retrotransposons are non-infectious, lack an envelope and remain intracellular. Ty1 retrotransposons belong to the copia elements (pseudoviridae). Produced by conventional translation.