Fig. 6

Mutations of the N-terminal coiled-coil domain of SIP. a Dimer stability scores (ΔΔG) of 10 mutants relative to the wt were calculated using MM-GBSA (X-axis) and Rosetta (Y-axis; REU denotes Rosetta Energy Units) methods. The decrease in ΔG relative to wildtype SIP (SIP wt; i.e., negative ΔΔG value) indicates an increase in dimer stability. Variants that were tested experimentally are shown in red. b Localization of two mutants that were tested experimentally in the SIP N-terminal domain. c Detection of SIP monomers and dimers in protein extracts from HEK293T cells that overexpressed wildtype SIP (SIP wt) or its variants that stabilized dimerization using native electrophoresis and Western blot (WB) and anti-SIP, anti-Flag, and anti-Myc antibodies. d, e Graphs show densitometric analysis of dimer/monomer ratio bands for K21W and T30R_S33E SIP variants compared with wt SIP and presented as fold changes. The results are expressed as mean ± SEM. *p < 0.05