2C3S:
reference: Structure of the SARS coronavirus main proteinase as an active C2 crystallographic dimer., Xu T, Ooi A, Lee HC, Wilmouth R, Liu DX, Lescar J, Acta Crystallograph Sect F Struct Biol Cryst Commun. 2005 Nov 1;61(Pt, 11):964-6. Epub 2005 Oct 20. PMID: 16511208

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