Figure 3.

Domain comparison of TRX-1, DNJ-27, PNG-1 and PDI-1. Thioredoxin superfamily members have at least one trx-like domain. The trx-like domains with the respective CXXC motif are shown in dark purple. Trx-like domains, which lack a CXXC motif are illustrated in light purple. DNJ-27 and PNG-1 have a J-domain (green) and transglutaminase domain (yellow), respectively. The position of the catalytic triad within the transglutaminase domain of PNG-1 is indicated.⁷⁶ Thioredoxins have a canonical CGPC motif whereas PDIs harbor the PDI-like motif CGHC in their active site. DNJ-27 combines both sequences in its structure. DNJ-27 and PDI-1 have an additional ER retention signal HDEL and HEEL, respectively.