Extended Data Fig. 1: In vitro functional characterization and cryo-EM analysis of the SPT complex.
From: Structural insights into the assembly and substrate selectivity of human SPT–ORMDL3 complex
a, Size exclusion chromatography (SEC) profile and Coomassie blue−stained SDS-PAGE gel corresponding to the last SPT complex purification step. The peak fractions indicated by the arrow were pooled and concentrated for biochemical and structural characterization. b, Initial rate of reaction versus L-serine concentration measured using the purified wild-type (WT) SPT complex or catalytic mutant (K379A in SPTLC2) SPT complex. Each data point is the average of three independent experiments, and error bars represent the SEM. The data points were fitted with a Michaelis-Menten equation. c, Initial rate of reaction versus palmitoyl-CoA concentration for the WT SPT complex. The data points were fitted with an allosteric sigmoidal equation. Please refer to the Methods section for details of the SPT activity assay. d, Representative cryo-EM micrograph and 2D class averages of the SPT complex. e, Flowchart for cryo-EM data processing. f, Angular distribution of the particles used to reconstruct the dimeric SPT complex. g, Gold-standard FSC curves for the dimeric (black curve) and monomeric (purple curve) SPT complexes generated using Relion 3.0. h, Local resolution maps of the dimeric (left) and monomeric (right) SPT complexes. The color code for resolution, shown with the unit Å, was calculated using Relion 3.0. Uncropped image for a and data for graphs b,c are available as source data.
