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	PROSITE documentation PDOC00640

Glycosyl hydrolases family 8 signature

The microbial degradation of cellulose and xylans requires several types of enzymes such as endoglucanases (EC 3.2.1.4), cellobiohydrolases (EC 3.2.1.91) (exoglucanases), or xylanases (EC 3.2.1.8) [1,2]. Fungi and bacteria produces a spectrum of cellulolytic enzymes (cellulases) and xylanases which, on the basis of sequence similarities, can be classified into families. One of these families is known as the cellulase family D [3] or as the glycosyl hydrolases family 8 [4,E1]. The enzymes which are currently known to belong to this family are listed below.

• Acetobacter xylinum endonuclease cmcAX.
• Bacillus strain KSM-330 acidic endonuclease K (Endo-K).
• Cellulomonas josui endoglucanase 2 (celB).
• Cellulomonas uda endoglucanase.
• Clostridium cellulolyticum endoglucanases C (celcCC).
• Clostridium thermocellum endoglucanases A (celA).
• Erwinia chrysanthemi minor endoglucanase y (celY).
• Bacillus circulans β-glucanase (EC 3.2.1.73).
• Escherichia coli hypothetical protein yhjM.

The most conserved region in these enzymes is a stretch of about 20 residues that contains two conserved aspartate. The first asparatate is thought [5] to act as the nucleophile in the catalytic mechanism. We have used this region as a signature pattern.

Expert(s) to contact by email:

Henrissat B.

Last update:

November 1997 / Text revised.

PROSITE method (with tools and information) covered by this documentation:

GLYCOSYL_HYDROL_F8, PS00812; Glycosyl hydrolases family 8 signature  (PATTERN)

• Consensus pattern:
  A-[ST]-D-[AG]-D-x(2)-[IM]-A-x-[SA]-[LIVM]-[LIVMG]-x-A-x(3)-[FW]
  The first D is an active site residue
• Sequences in UniProtKB/Swiss-Prot known to belong to this class: 16
  • detected by PS00812: 13 (true positives)
  • undetected by PS00812: 3 (2 false negatives and 1 'partial')
• Other sequence(s) in UniProtKB/Swiss-Prot detected by PS00812:
  NONE.
• Retrieve an alignment of UniProtKB/Swiss-Prot true positive hits:
  Clustal format, color, condensed view  /  Clustal format, color  /  Clustal format, plain text  /  Fasta format
• Retrieve the sequence logo from the alignment
• Taxonomic distribution of all UniProtKB (Swiss-Prot + TrEMBL) entries matching PS00812
• Retrieve a list of all UniProtKB (Swiss-Prot + TrEMBL) entries matching PS00812
• Scan UniProtKB (Swiss-Prot and/or TrEMBL) entries against PS00812
• View ligand binding statistics of PS00812
• Matching PDB structures: 1CEM 1IS9 1KWF 1WZZ ... [ALL]

1	Authors	Beguin P.
	Title	Molecular biology of cellulose degradation.
	Source	Annu. Rev. Microbiol. 44:219-248(1990).
	PubMed ID	2252383
	DOI	10.1146/annurev.mi.44.100190.001251

2	Authors	Gilkes N.R., Henrissat B., Kilburn D.G., Miller R.C. Jr., Warren R.A.J.
	Title	Domains in microbial beta-1, 4-glycanases: sequence conservation, function, and enzyme families.
	Source	Microbiol. Rev. 55:303-315(1991).
	PubMed ID	1886523

3	Authors	Henrissat B., Claeyssens M., Tomme P., Lemesle L., Mornon J.-P.
	Title	Cellulase families revealed by hydrophobic cluster analysis.
	Source	Gene 81:83-95(1989).
	PubMed ID	2806912

4	Authors	Henrissat B.
	Title	A classification of glycosyl hydrolases based on amino acid sequence similarities.
	Source	Biochem. J. 280:309-316(1991).
	PubMed ID	1747104

5	Authors	Alzari P.M., Souchon H., Dominguez R.
	Title	The crystal structure of endoglucanase CelA, a family 8 glycosyl hydrolase from Clostridium thermocellum.
	Source	Structure 4:265-275(1996).
	PubMed ID	8805535

E1	Title	https://www.uniprot.org/docs/glycosid
	Source	?

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