3QPB:
reference: The Crystal Structure of Streptococcus pyogenes Uridine Phosphorylase Reveals a Distinct Subfamily of Nucleoside Phosphorylases., Tran TH, Christoffersen S, Allan PW, Parker WB, Piskur J, Serra I, Terreni M, Ealick SE, Biochemistry. 2011 Aug 2;50(30):6549-6558. Epub 2011 Jul 8. PMID: 21707079

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