2I68:
reference: Quasi-symmetry in the Cryo-EM Structure of EmrE Provides the Key to Modeling its Transmembrane Domain., Fleishman SJ, Harrington SE, Enosh A, Halperin D, Tate CG, Ben-Tal N, J Mol Biol. 2006 Nov 17;364(1):54-67. Epub 2006 Aug 30. PMID: 17005200

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