string: …family, from both prokaryotic and eukaryotic origin, an unequivocal assignment of functional states to these conformations has not been achieved (Unwin and Fujiyoshi, 2012; Du et al., 2015; Hilf and Dutzler, 2009, 2008; Sauguet et al., 2013; Bocquet et al., 2009; Miller and Aricescu, 2014;…