2H1M:
reference: Synthesis, Oxidation Behavior, Crystallization and Structure of 2'-Methylseleno Guanosine Containing RNAs., Moroder H, Kreutz C, Lang K, Serganov A, Micura R, J Am Chem Soc. 2006 Aug 2;128(30):9909-18. PMID: 16866550

This OCA Structure page
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