9RXW

Ty1 Prime Retrotransposon Capsid C-Terminal Domain, wt

Summary for 9RXW

• Entry DOI: 10.2210/pdb9rxw/pdb
• Descriptor: Capsid protein (2 entities in total)
• Functional Keywords: capsid, gag, retrotransposon, virus like particle
• Biological source: Saccharomyces cerevisiae (brewer's yeast)
• Total number of polymer chains: 2
• Total formula weight: 22254.85

Authors

Cottee, M.A.,Taylor, I.A. (deposition date: 2025-07-13, release date: 2025-10-08, Last modification date: 2025-10-22)

Primary citation

Beckwith, S.L.,Cottee, M.A.,Hannon-Hatfield, J.A.,Newman, A.C.,Walker, E.C.,Romero, J.R.,Stoye, J.P.,Taylor, I.A.,Garfinkel, D.J.
Probing the molecular determinants of Ty1 retrotransposon restriction specificity in yeast.
Plos Genet., 21:e1011898-e1011898, 2025

PubMed Abstract: The evolutionary history of retrotransposons and their hosts shapes the dynamics of transposition and restriction. The Pseudoviridae of yeast includes multiple Ty1 LTR-retrotransposon subfamilies. Saccharomyces cerevisiae prevents uncontrolled retrotransposition of Ty1 subfamilies using distinct mechanisms: canonical Ty1 is inhibited by a self-encoded restriction factor, p22/p18, whereas Ty1' is inhibited by an endogenized restriction factor, Drt2. The minimal inhibitory fragment of both restriction factors (p18m and Drt2m) is a conserved C-terminal capsid domain. Here, we use biophysical and genetic approaches to demonstrate that p18m and Drt2m are highly specific to their subfamilies. Although the crystal structures of p18m and Drt2m are similar, three divergent residues found in a conserved hydrophobic interface direct restriction specificity. By mutating these three residues, we re-target each restriction factor to the opposite transposon. Our work highlights how a common lattice-poisoning mechanism of restriction evolved from independent evolutionary trajectories in closely related retrotransposon subfamilies. These data raise the possibility that similar capsid-capsid interactions may exist in other transposons/viruses and that highly specific inhibitors could be engineered to target capsid interfaces.

PubMed: 41066520
DOI: 10.1371/journal.pgen.1011898

Experimental method

X-RAY DIFFRACTION (1.6 Å)