Fig. 4: MccV interacts with an electropositive pocket in the Cir loops.
From: Structural insights into Cir-mediated killing by the antimicrobial protein Microcin V
Three arginine residues (Arg 436 from loop 7, Arg 490 from loop 8, and Arg 116 from the plug) form an electropositive cavity within the Cir ligand-binding pocket. When in complex, the sidechain of aspartate 85 from MccV fills the space inside the cavity, creating a putative electrostatic interaction. A, B A shot-reverse shot illustration of the interacting residues shown as cartoon (top) and with electrostatic surface colored (bottom). Arginine cavity electropositive surface is shown on the left of panel B, with the electronegative Asp 85 surface shown on the right. C, D Asp 85 settles in close proximity to the Cir aspartates. Atomic distances between the relevant atoms of Asp 85 and each of the arginines were determined and are illustrated in (C), with sidechain heteroatom surfaces shown in (D). Interactions shown: R116 NH1 with D85 OD2, R436 NE with D85 OD2, and R490 NH2 with D85 OD1.
