User:Amy Kerzmann/Sandbox 2

From Proteopedia

Revision as of 21:14, 24 September 2009

Voltage-gated Potassium Channel

Template:STRUCTURE 3cs9 Backgound

This crystal structure illuminated the principles of ion selectivity when it was solved in 1998.^[1] To further demonstrate the importance of this structure, the 2003 Nobel Prize in Chemistry was awarded to the principal investigator, Roderick MacKinnon.

Channel Structure:

The potassium channel is a homotetramer, meaning that it is comprised of four identical .

The central core of this protein is comprised of eight helices, two from each monomeric subunit. Since each has the same orientation in the membrane, the protein has a four-fold rotational symmetry when viewed from the membrane surface. As a result, each of the channel-lining residues appears as a ring of four identical sidechains. This principle is represented by the conserved residues that function as selectivity filters within the cavity. Additional and residues line the channel. Looking at a of these residues, one can see that some hydrophobic patches remain within the cavity.

Channel Function:

Here's how it works.

References

1. ↑ Doyle DA, Morais Cabral J, Pfuetzner RA, Kuo A, Gulbis JM, Cohen SL, Chait BT, MacKinnon R. The structure of the potassium channel: molecular basis of K+ conduction and selectivity. Science. 1998 Apr 3;280(5360):69-77. PMID:9525859