Noncanonical usage of stop codons in ciliates expands proteins with structurally flexible Q-rich motifs
Serine(S)/threonine(T)-glutamine(Q) cluster domains (SCDs), polyglutamine (polyQ) tracts and polyglutamine/asparagine (polyQ/N) tracts are Q-rich motifs found in many proteins.SCDs often are intrinsically disordered regions that mediate protein phosphorylation and protein-protein interactions.PolyQ and polyQ/N tracts are structurally flexible seque