Fig. 1.

Domain organization of human PDI proteins. Arrangement of TRX-like domains and ER-retention sequence in 21 members of the human PDI gene family are shown here. The catalytically active a-type domains (a and a’) are depicted as black boxes with the active site motif sequences shown inside and the catalytically inactive b-type domains (b and b’) are depicted as gray boxes. ER-retention sequences are depicted as white boxes with the motif sequences shown inside. The N-terminal signal sequences and other functional domains present in certain PDI proteins are not shown.