CBD_II

• SMART accession number: SM00637
• Interpro abstract (IPR001919):

  The microbial degradation of cellulose and xylans requires several types of enzyme such as endoglucanases (EC 3.2.1.4), cellobiohydrolases (EC 3.2.1.91) (exoglucanases), or xylanases (EC 3.2.1.8) (PUBMED:1886523). Structurally, cellulases and xylanases generally consist of a catalytic domain joined to a cellulose-binding domain (CBD) by a short linker sequence rich in proline and/or hydroxy-amino acids.

  The CBD domain is found either at the N-terminal or at the C-terminal extremity of these enzymes. As it is shown in the following schematic representation, there are two conserved cysteines in this CBD domain - one at each extremity of the domain - which have been shown (PUBMED:1761039) to be involved in a disulphide bond. There are also four conserved tryptophan, two are involved in cellulose binding. The CBD of a number of bacterial cellulases has been shown to consist of about 105 amino acid residues (PUBMED:1812490), (PUBMED:10973978).

             +-------------------------------------------------+
             |                                                 |
            xCxxxxWxxxxxNxxxWxxxxxxxWxxxxxxxxWNxxxxxGxxxxxxxxxxCx
  
  'C': conserved cysteine involved in a disulphide bond.
  

• GO process: carbohydrate metabolic process (GO:0005975)
• GO function: carbohydrate binding (GO:0030246), hydrolase activity, hydrolyzing O-glycosyl compounds (GO:0004553)

There are 284 CBD_II domains in 266 proteins in SMART's nrdb database.

Metabolism (metabolic pathways involving proteins which contain this domain)

% proteins involved	KEGG pathway ID	Description
69.57	map00500	Starch and sucrose metabolism
30.43	map00530	Aminosugars metabolism

This information is based on mapping of SMART genomic protein database to KEGG orthologous groups. Percentage points are related to the number of proteins with CBD_II domain which could be assigned to a KEGG orthologous group, and not all proteins containing CBD_II domain. Please note that proteins can be included in multiple pathways, ie. the numbers above will not always add up to 100%.

Structure (3D structures containing this domain)

3D Structures of CBD_II domains in PDB

PDB code	Title
1e5b	Internal xylan binding domain from c. fimi xyn10a, r262g mutant
1e5c	Internal xylan binding domain from c. fimi xyn10a, r262g mutant
1exg	Solution structure of a cellulose binding domain from cellulomonas fimi by nuclear magnetic resonance spectroscopy
1exh	Solution structure of a cellulose binding domain from cellulomonas fimi by nuclear magnetic resonance spectroscopy
1heh	C-terminal xylan binding domain from cellulomonas fimi xylanase 11a
1hej	C-terminal xylan binding domain from cellulomonas fimi xylanase 11a
1xbd	Internal xylan binding domain from cellulomonas fimi xylanase d, nmr, 5 structures
2cwr	Crystal structure of chitin biding domain of chitinase from pyrococcus furiosus
2czn	Solution structure of the chitin-binding domain of hyperthermophilic chitinase from pyrococcus furiosus
2xbd	Internal xylan binding domain from cellulomonas fimi xylanase d, nmr, minimized average structure

Links (links to other resources describing this domain)

• INTERPRO: IPR001919