The cellulosome is a multi-enzyme structure secreted by anaerobic microorganisms for the degradation of lignocellulosic substrates. The Cohesin (Coh)-Dockerin (Doc) interactions are the main driving force for cellulosome assembly and are among the strongest protein-protein interactions in nature. Due to a distinctive two-fold internal symmetry, Doc can bind its Coh partner in two different orientations (dual-binding mode). By combining structural characterization (X-ray crystallography) with affinity studies, we have uncovered the molecular mechanisms governing the dual-binding mode and found that the single vs. dual binding mode does not appear to be related to Coh-Doc type or function but rather to cellulosome size and complexity.

The research of Dr. Bule focuses on the discovery and characterization of novel CAZymes and cellulosomal proteins, as well as the creation of new glycan-based technologies with applications ranging from cancer immunotherapy to microbiology to animal nutrition.