2E1P:
reference: Crystal structure of unautoprocessed precursor of subtilisin from a hyperthermophilic archaeon: evidence for Ca2+-induced folding., Tanaka S, Saito K, Chon H, Matsumura H, Koga Y, Takano K, Kanaya S, J Biol Chem. 2007 Mar 16;282(11):8246-55. Epub 2007 Jan 19. PMID: 17237225

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