4QJC:
reference: Structure-activity correlations for three pyrido[2,3-d]pyrimidine antifolates binding to human and Pneumocystis carinii dihydrofolate reductase., Cody V, Pace J, Namjoshi OA, Gangjee A, Acta Crystallogr F Struct Biol Commun. 2015 Jun 1;71(Pt 6):799-803. doi:, 10.1107/S2053230X15008468. Epub 2015 May 27. PMID: 26057816

This OCA Structure page
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