Fig. 1: Structures of GPI-T in complex with substrates and products.
From: Structures of liganded glycosylphosphatidylinositol transamidase illuminate GPI-AP biogenesis
a Schematic representation of GPI-T’s reaction. The ω-site residues are listed in the box by their occurrence rate13 from high to low. The preferences for the, ω+1, ω+2, and ω+3 residues (single-letter abbreviations) are indicated in the dashed box. A “+/-” sign indicates the optional Man4 modification for human GPIs. Amino acid residues in the C-terminal signal peptide (CSP) are abbreviated as single letters. ER, endoplasmic reticulum; EtNP, ethanolamine phosphate; GlcN, glucosamine; Ino, inositol; Man, mannose. b PI-PLC sensitivity assay of ULBP2 mutants. The staining of HA-tagged wild-type (WT), and single and double glutamine mutants of Ser216/Ser217 on HEK293 cells treated with (red) or without (cyan) PI-PLC were assessed using fluorescently labeled anti-HA antibodies using fluorescence-activated cell sorting. The grey dashed line indicates background staining. See Supplementary Fig. 15a for the gating strategy. PI-PLC, phosphatidylinositol-specific phospholipase C. c, d Cryo-EM map of GPI-T with substrates c and products d. The density corresponding to various components is color-coded as indicated. The catalytic dyad residues are indicated by a yellow dot.
