Figure 1.

Schematic overview of the human protein disulphide isomerase family. Thioredoxin-like domains are represented by rectangles with the active-site sequence added for catalytic domains (yellow). The catalytically inactive b′ domain is shown in blue and other catalytically inactive domains are in green. The linker region between b′ and a′ domains is coloured in grey, and transmembrane regions are shown in red. Signal sequences are not shown. Note that the catalytic domain of ERp18 contains a putative 23-amino-acid insert between β3 and α3 (Alanen et al, 2003) that is not shown in the figure.