Figure 3

Characteristics of the identified proteins. (a) Comparison of pI distributions for the already known, and enriched NABPs in our data (solid green line) versus all Swiss-Prot human proteins (dashed black line) and known human NABPs in Swiss-Prot (dashed green line). NABPs without nucleic acid binding GO annotation (solid red line) had a more pronounced shift towards higher values, whereas the likely secondary binders had the opposite trend (solid blue line). (b) Sequence conservation as determined by the number of orthologs reported in Ensembl. Compared to all the enriched proteins (left gray box), the newly identified NABPs were significantly less evolutionarily conserved (*** P < 0.005, KS test) and the RNA-specific NABPs more conserved (* P < 0.05, KS test). The other groups showed no significant difference. RNA-specific NABPs contain many ribosomal proteins, which explain the average higher conservation.