1FMU:
reference: An unusual orientation for Tyr75 in the active site of the aspartic proteinase from Saccharomyces cerevisiae., Gustchina A, Li M, Phylip LH, Lees WE, Kay J, Wlodawer A, Biochem Biophys Res Commun 2002 Jul 26;295(4):1020-6. PMID: 12127998

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