Extended Data Fig. 4: I− binds to a partially positively charged cavity.
From: Structural insights into the mechanism of the sodium/iodide symporter

a. NIS-I− side view. The solvent accessible surface is colored according to the electrostatic potential using a double gradient between −2 EV (red) and 0 (white) and between 0 and 2 EV (blue) and cropped to expose the I− binding cavity. b. Close-up of the I− binding cavity showing the positive nature of its surface.