Unravelling intrinsically disordered and compositionally biased proteins in the cereal proteomes

Intrinsically disordered proteins (IDPs) play key biological functions despite lacking predetermined 3D structures. They are often compositionally biased and characterized by specific amino acid compositions. Here, we investigated protein intrinsic disorder in rice, wheat, barley, maize, sorghum, oat and rye proteomes. Then, we studied the distribution of compositionally biased proteins (CBs) in these species. The data showed that the contents of compositional biased proteins (CB), the average protein sizes, and biased sequence sizes were similar in the studied proteomes. Furthermore, the CB proteins were enriched in intrinsic disorder and IDPs were characterized by noticeable composition biases. In addition, the polar and the charged residues were the most abundant among the types of the biased residues. Gene Ontology analysis revealed that CB proteins in the studied species are mainly involved in binding, catalytic activity, and transcription regulation. Altogether, our findings indicated that there is a noticeable conservation of intrinsically disordered and CB proteins in cereals. The evolutionary conservation of these features implies that cereals may use common cellular and regulatory mechanisms to adapt to various environmental constraints.