Single potassium ion seeks open channel for transmembrane travels: tales from the KcsA structure.

Potassium channels selectively catalyze potassium transport across cell membranes. Over the past five decades, a multitude of potassium channel models have been proposed. The recent crystal structure determination of the KcsA potassium channel confirms, corrects and expands our understanding of a fundamental biological catalyst, revealing the basis of exquisite selectivity and near diffusion-limited throughput.