Figure 4: Crystal structure of a TTC7B/FAM126A co-complex reveals an unusually large protein–protein interface and a conserved binding surface for PI4KIIIα.
From: The leukodystrophy protein FAM126A (hyccin) regulates PtdIns(4)P synthesis at the plasma membrane
(a) Ribbon diagram for the TTC7B/FAM126A-N complex. Note the FAM126A-N hairpin structure that wraps around TTC7B like an arm. Point mutations in FAM126A that underlie HCC are indicated in Supplementary Fig. 3c. (b) Ribbon diagrams for TTC7B and FAM126A-N coloured from blue (N terminus) to red (C terminus). The ‘arm’ in FAM126A is green. Disordered residues absent from the model are indicated by dotted lines. (c) Space-filling models of the TTC7B/FAM126A-N complex (left) and TTC7B (middle and right) coloured by sequence conservation. Conserved surfaces on TTC7B/FAM126A-N (yellow outline) or TTC7B alone (orange outline) that may interact with PI4KIIIα are circled (left). The TTC7B surfaces at the interface with FAM126A-N are indicated by dotted yellow lines (middle and right). (d) Model for PI4KIIIα assembly at the plasma membrane. The EFR3 model is based on the structure of yeast Efr3 (ref. 20) (PDBID 4N5A).
