FIG 8.

UL37N shares structural similarities with several subunits of cellular MTCs. (A) UL37N is shown side by side with the Tip20 (PDB accession no. 3FHN) and Dsl1 (PDB accession no. 3K8P) subunits of the Dsl1 complex and the Sec6 (PDB accession no. 2FJI) and Exo70 (PDB accession no. 2B7M) subunits of the exocyst complex, with the Z-score for each alignment displayed. Structure alignments were carried out using the Dali server (42). Domain I of UL37N aligns with domain C of these proteins (green). The overall J shape of domains I and II of UL37N is reminiscent of these MTC components. (B) Overlays of regions of Tip20, Sec6, and Dsl1 that align onto residues 1 to 136 of UL37N. (C) The salt bridge in domain II between putative D and E subdomains of UL37N is strictly conserved among alphaherpesviruses and likely plays a structural role. This salt bridge resembles the interdomain salt bridge between residues R729 and E764 of Cog4 subunit (PDB accession no. 3HR0) of the COG complex (48).