Updated project metadata. The major peanut allergen Ara h 2 undergoes site-specific hydroxylation at three proline residues within repetitive IgE-binding DPYSPOHS sequences. There has been no report of recombinant Ara h 2 production with hydroxyprolines until now. We produced recombinant Ara h 2 in N. benthamiana leaves to determine host-related contaminants and to analyze site-specific hydroxylation of proline residues.