哺乳動物腺核三磷酸感受性鉀離子通道晶體繞射結構性質之研究

Abstract

Rundown is a generally encountered problem while recording KATP channel activity with inside-out patches. No assigned structural fragment related to this mechanism has yet been derived from any of the functional analyses performed. Therefore, based on a combined sequence and secondary structure alignment against known crystal structure of segments from closely related proteins, we propose here the three-dimensional structural model of an intracellular C-terminal domain of the Kir6.2 subunit in KATP channels. An E. coli CMPkinase was suggested as template for the model building. The subdomain arrangement of this novel kinase domain and the structural correlation for UDP-docking are described. With structural-functional interpretation, we conclude that the reactivation of KATP channel rundown by MgATP or UDP is very possibly regulated by this intracellular kinase domain at the C-terminus of Kir6.2 subunit in KATP channels.