1IBQ:
reference: Structure of aspergillopepsin I from Aspergillus phoenicis: variations of the S1'-S2 subsite in aspartic proteinases., Cho SW, Kim N, Choi MU, Shin W, Acta Crystallogr D Biol Crystallogr 2001 Jul;57(Pt 7):948-56. PMID: 11418762

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