Figure 3
From: Structure based analysis of KATP channel with a DEND syndrome mutation in murine skeletal muscle
Arg50 plays pivotal roles in ATP binding from structural analyses. (a) The overall structure of the Kir6.2 tetramer extracted from the KATP channel (6BAA, 6JB1) drawn with PyMol (http://pymol.sourceforge.net/), both of which are solved with the highest resolution reported thus far (6BAA, 3.6 Å; 6JB1, 3.3 Å). The structure clearly reveals that the Arg50 residue is located at the loop region for twining around the subsequent Kir6.2 subunit. The side chain of Arg50 electrostatically interacts with the gamma phosphate group of ATP in 6BAA, whereas the residue extensively interacts with beta and gamma phosphate groups in ATP. (b–d) Representative interactions between Arg50 and alpha/beta/gamma phosphate groups in ATP drawn with VMD55. (e–g) The distance between Arg50 HH12–ATP O3A (e), Arg50 HH12–ATP O3B (f), Arg50 HH12–ATP O3G (g) were measured for 500 ns molecular dynamics simulation. All plots were produced with xmgrace (http://plasma-gate.weizmann.ac.il/Grace/). Analyses for other monomers and replicas are presented in the Supplementary Materials.
