Fig. 3: Analysis of GH complexes.

a, Separation of cellulase and xylanase complexes eluted from an anion-exchange chromatography column at 260 mM NaCl and visualized by 2D BN–PAGE⁵⁸. Complexes containing S-Layer proteins (S), CMCase (C) and xylanase (X) activity were separated in the first dimension according to their indicated masses by BN–PAGE. Protein staining was accompanied by zymography with gels embedded with CMC and xylan. b, Subunits of the native complexes were separated in a second dimension by SDS–PAGE (8%) and identified as CelABC and XynA by proteomics. The XynA molecular weight (~80 kDa) is indicative of a truncation of the full-length protein (100 kDa). Zymography with CMC revealed the activity of bands corresponding to CelC and CelA. c, GH complexes enriched by affinity digestion were separated by BN–PAGE and protein stains were accompanied by zymography with gels embedded with CMC and xylan. d, Native complexes were separated by SDS–PAGE into subunits CelABC and visualized by protein and CMCase activity staining. e, SDS–PAGE was also performed without initial heat denaturation, and three abundant individual complexes with different compositions of CelABC were identified by proteomics. Detailed proteomics data are provided in Supplementary Figs. 8 and 9. Images were cropped for clarity. Each gel is representative of five gels performed on multiple protein preparations. Gels stained with Coomassie and analysed by zymography were run in parallel in the same electrophoretic cell to ensure comparability. The gels in this figure are from one individual protein preparation for each of the two purification techniques described in the text. The gel images were cropped for clarity and the original gel images are provided in Supplementary Fig. 14.