Minimal art: Or why small viral K⁺ channels are good tools for understanding basic structure and function relations

Some algal viruses contain genes that encode proteins with the hallmarks of K⁺ channels. One feature of these proteins is that they are less than 100 amino acids in size, which make them truly minimal for a K⁺ channel protein. That is, they consist of only the pore module present in more complex K⁺ channels. The combination of miniature size and the functional robustness of the viral K⁺ channels make them ideal model systems for studying how K⁺ channels work. Here we summarize recent structure/function correlates from these channels, which provide insight into functional properties such as gating, pharmacology and sorting in cells.