Figure 5: Substrate recognition by the GC domain active site.

(a) Difference electron-density map for the oligosaccharide bound at the GC domain active site. (b) Accommodation of this oligosaccharide by the GC domain. (c) Specific debranching activities of CgGDE mutants R1123G and Y1407F, and their combinations with mutants possessing only the GT or GC activities.