Fig. 3.

The role of the C-termini of P3H1 and CRTAP in forming a complex with PPIB. a Partially purified PD4/CRTAP was mixed with Sumo-PPIB and then analyzed by a Superose 6 gel filtration column with eluted fractions analyzed by coomassie-stained SDS-PAGE. This shows that PPIB can readily form ternary complex with the secreted PD4/CRTAP and was eluted in the early peak with PD4/CRTAP. b–d The partially purified PD4/CRTAP or PD4-His/CRTAP or PD4/CRTAP-His were mixed with Sumo-PPIB and then directly analyzed by gel filtration. The elution positions of PD4, CRTAP, and Sumo-PPIB were analyzed by SDS-PAGE and western blot. Complex formation in fraction 13 and 14 was observed from PD4/CRTAP/Sumo-PPIB in b, as seen in a, but not from the mixture of Sumo-PPIB with PD4-His/CRTAP (c) or PD4/CRTAP-His (d). All experiments were performed ≥ 3 times independently