Fig. 6: The binding mode of diltiazem to Organic Cation Transporter 1 involves E386.
From: Structural basis of promiscuous substrate transport by Organic Cation Transporter 1

a Interactions in OCT1-DTZ, with coordination of Q241, Y361, and E386 to the ammonium group of diltiazem. b Summary of interactions in the binding pocket of OCT1 with diltiazem.