Plays an important role in the elongation step of protein synthesis. P1 and P2 exist as dimers at the large ribosomal subunit. Causes an allergic reaction in human (PubMed:16088208, PubMed:19248220, PubMed:23902156). Binds to IgE of patients allergic to mold P.brevicompactum (PubMed:16088208). Binds to IgE in 73% of the 41 Penicillium-sensitive patients tested (PubMed:19248220). Binds to IgE in 87% of the 61 patients tested allergic to Penicillium mold (PubMed:23902156). Belongs to the eukaryotic ribosomal protein P1/P2 family.