Figure 1.

Structure of Ega3 reveals a modified (β/α)₈-barrel fold with a deep highly-conserved cleft. A, predicted domain arrangement of Ega3. B, crystal structure of (β/α)₈-barrel fold of Ega3 shown in cartoon representation. The (β/α)-barrel is colored in blue (β-strands) and teal (α-helices) with the five N-glycans that could be built into the electron density displayed as gray sticks. The secondary structure elements of the β3-insertion are shown in dark red, and the three disulfide bonds are shown in yellow. The missing elements typically found in a (β/α)₈-barrel, β5, α1, and α8, are labeled in bold and italic. C, surface representation colored from variable in teal to conserved in fuchsia, as calculated by Consurf (91). D, electrostatic surface, calculated using APBS in PyMOL, shows a highly negatively charged cleft (+10 kT to −10 kT) (60).