1YU6:
reference: Structure of the subtilisin Carlsberg-OMTKY3 complex reveals two different ovomucoid conformations., Maynes JT, Cherney MM, Qasim MA, Laskowski M Jr, James MN, Acta Crystallogr D Biol Crystallogr. 2005 May;61(Pt 5):580-8. Epub 2005, Apr 20. PMID: 15858268

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