On the cover: Substrate-binding cleft of the important house dust mite allergen Der p 1 (orange) superimposed with inhibitor-bound papain (violet). The inhibitor (yellow) is bound to the catalytic cysteine. The structure of proDer p 1 provides novel insight into the folding, enzymatic properties, and effect of the propeptide on Ab binding. Meno, K., P. B. Thorsted, H. Ipsen, O. Kristensen, J. N. Larsen, M.D. Spangfort, M. Gajhede, and K. Lund. 2005. The crystal structure of recombinant proDer p 1, a major house dust mite proteolytic allergen. J. Immunol.175: 3835–3845.