1SKM:
reference: Caught in the act: visualization of an intermediate in the DNA base-flipping pathway induced by HhaI methyltransferase., Horton JR, Ratner G, Banavali NK, Huang N, Choi Y, Maier MA, Marquez VE, MacKerell AD Jr, Cheng X, Nucleic Acids Res 2004 Jul 23;32(13):3877-86. Print 2004. PMID: 15273274

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