3VYI:
reference: Gating of the designed trimeric/tetrameric voltage-gated H+ channel., Fujiwara Y, Kurokawa T, Takeshita K, Nakagawa A, Larsson HP, Okamura Y, J Physiol. 2013 Feb 1;591(Pt 3):627-40. doi: 10.1113/jphysiol.2012.243006. Epub, 2012 Nov 19. PMID: 23165764

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