TCB Publications - Abstract

TCB Publications - Abstract

Raymond E Hulse, Joseph R Sachleben, Po-Chao Wen, Mahmoud Moradi, Emad Tajkhorshid, and Eduardo Perozo. Conformational dynamics at the inner gate of KcsA during activation. Biochemistry, 53:2557-2559, 2014. (PMC: PMC4010282)

HULS2014-ET The potassium channel KcsA offers a unique opportunity to explicitly study the dynamics of the moving parts of ion channels, yet our understanding of the extent and dynamic behavior of the physiologically relevant structural changes at the inner gate in KcsA remains incomplete. Here, we use electron paramagnetic resonance, nuclear magnetic resonance, and molecular dynamics simulations to characterize the extent of pH- dependent conformational changes of the inner gate in lipid bilayers or detergent micelles. Our results show that under physiological conditions the inner gate experiences a maximal diagonal opening of $\sim$24 Åwith the largest degree of dynamics near the pKa of activation (pH $\sim$3.9). These results extend the observation that the C-terminus is necessary to limit the extent of opening and imply that the inner gate regulates the extent of conformational change at the zone of allosteric coupling and at the selectivity filter.

Download Full Text

The manuscripts available on our site are provided for your personal use only and may not be retransmitted or redistributed without written permissions from the paper's publisher and author. You may not upload any of this site's material to any public server, on-line service, network, or bulletin board without prior written permission from the publisher and author. You may not make copies for any commercial purpose. Reproduction or storage of materials retrieved from this web site is subject to the U.S. Copyright Act of 1976, Title 17 U.S.C.

Download full text: Journal, Request a Copy