Fig. 4: Structural Basis of COP-1 Recognition of Human Claudin-4.
From: Structural and biophysical insights into targeting of claudin-4 by a synthetic antibody fragment
a The cryo-EM map from the hsCLDN-4/cCpE/COP-1/Nb complex (gray) contoured to show the experimentally determined boundary of the detergent belt with predicted membrane boundary from the PPM server (black dots)45 and structure overlayed for reference. Zoom-in of the interface between hsCLDN-4 (teal) and COP-1 (blue) showing density for a modeled LMNG detergent. The chemical structure of LMNG in a stick representation is also shown with carbons (black) and oxygens (red) colored accordingly. b Interactions between hsCLDN-4 and COP-1. The predicted PPM membrane boundary (black dots) overlaid on the structure of hsCLDN-4/cCpE/COP-1/Nb complex with hsCLDN-4 (teal), cCpE (gold), COP-1 (blue), and NB (gray), and LMNG colored accordingly as in (a). Side chains of significance are labeled and shown for reference. c Zoom-in on the structure of COP-1s CDR-H3 amphipathic helix showing π-π stacking and associated membrane penetration. d Interactions between COP-1s H (dark blue) and L (light blue) chains with the ECS1 region of hsCLDN-4.
