F5/8 type C domain. This domain is also known as the discoidin (DS) domain family.

Substituted updates: Jan 31, 2002

Putative binding domain, N-terminal. The BACON (Bacteroidetes-Associated Carbohydrate-binding Often N-terminal) domain is an all-beta domain found in diverse architectures, principally in combination with carbohydrate-active enzymes and proteases. These architectures suggest a carbohydrate-binding function which is also supported by the nature of BACON's few conserved amino-acids. The phyletic distribution of BACON and other data tentatively suggest that it may frequently function to bind mucin. Further work with the characterized structure of a member of glycoside hydrolase family 5 enzyme, Structure 3ZMR, has found no evidence for carbohydrate-binding for this domain.

Bacteroidetes-Associated Carbohydrate-binding (putative) Often N-terminal (BACON) domain. The BACON domain is found in diverse domain architectures and accociated with a wide variety of domains, including carbohydrate-active enzymes and proteases. It was named for its suggested function of carbohydrate binding; the latter was inferred from domain architectures, sequence conservation, and phyletic distribution. However, recent experimental data suggest that its primary function in Bacteroides ovatus endo-xyloglucanase BoGH5A is to distance the catalytic module from the cell surface and confer additional mobility to the catalytic domain for attack of the polysaccharide. No evidence for a direct role in carbohydrate binding could be found in that case. The large majority of BACON domains are found in Bacteroidetes.

Coagulation factor 5/8 C-terminal domain, discoidin domain. Cell surface-attached carbohydrate-binding domain, present in eukaryotes and assumed to have horizontally transferred to eubacterial genomes.