1RGS:
reference: Regulatory subunit of protein kinase A: structure of deletion mutant with cAMP binding domains., Su Y, Dostmann WR, Herberg FW, Durick K, Xuong NH, Ten Eyck L, Taylor SS, Varughese KI, Science 1995 Aug 11;269(5225):807-13. PMID: 7638597

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