Reference:
Mannikko R, Stansfeld PJ, Ashcroft AS, Hattersley AT, Sansom MS, Ellard S, Ashcroft FM. A conserved tryptophan at the membrane-water interface acts as a gatekeeper for Kir6.2/SUR1 channels and causes neonatal diabetes when mutated. Journal of Physiology 2011;589(13): 3071-3083.