4ADX:
reference: Cryo-EM Structure of the Archaeal 50S Ribosomal Subunit in Complex with Initiation Factor 6 and Implications for Ribosome Evolution., Greber BJ, Boehringer D, Godinic-Mikulcic V, Crnkovic A, Ibba M, Weygand-Durasevic I, Ban N, J Mol Biol. 2012 May 4;418(3-4):145-60. Epub 2012 Jan 27. PMID: 22306461

This OCA Structure page
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