Fig. 7.

NP-P-L complex formation. (A) Interaction between NP and P/P mutants. BSR-T7 cells were transfected with NP together with P or a P mutant. After labeling with ³⁵S-Cys-Met, the cells were lysed and the supernatants were incubated with antibody against P or NP for coimmunoprecipitation. (B) IP-IB data showing the interaction between Flag-L and P/P-T286A/P-T286E/P-T286D. Pk antibody, which recognizes P, was used for IP, and mouse anti-Flag was used for IB. (C) Tetramer formation of P or P mutants. The transfected BSR-T7 cells were starved and labeled with [³⁵S]Met/Cys. The cells were incubated with DSP to cross-link the S-S band to stabilize the P tetramer. The lysate was incubated with Pk and resolved in SDS-PAGE with or without DTT. The gel was dried, and the proteins were visualized using a Typhoon 9700 system.