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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 B [3] or as the glycosyl hydrolases family 6 [4,E1]. The enzymes which are currently known to belong to this family are listed below.

• Agaricus bisporus exoglucanase 3 (cel3).
• Cellulomonas fimi endoglucanase A (cenA).
• Cellulomonas fimi exoglucanase A (cbhA).
• Microspora bispora endoglucanase A (celA).
• Streptomyces halstedii endoglucanases A (celA1).
• Streptomyces strain KSM-9 endoglucanase 1 (casA).
• Thermomonospora fusca endoglucanase E-2 (celB).
• Trichoderma reesei exoglucanase II (CBH2).

One of the conserved regions in these enzymes contains a conserved aspartic acid residue which is potentially involved [5] in the catalytic mechanism; the aspartate is followed by a cysteine which is involved in a disulfide bond [6]. A second conserved region contains an aspartate which seems [5] to be the proton donor in the catalytic mechanism. We have used both regions as signature patterns.

Henrissat B.

May 2004 / Text revised.

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

GLYCOSYL_HYDROL_F6_1, PS00655; Glycosyl hydrolases family 6 signature 1  (PATTERN)

Consensus pattern: V-x-Y-x(2)-P-x-R-D-C-[GSAF]-x(2)-[GSA](2)-x-G D may be an active site residue; C is involved in a disulfide bond Sequences known to belong to this class detected by the pattern: ALL, except for celA1 Other sequence(s) detected in Swiss-Prot: NONE.

• Retrieve an alignment of 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 tree view of all Swiss-Prot/TrEMBL entries matching PS00655 • Retrieve a list of all Swiss-Prot/TrEMBL entries matching PS00655 • Scan Swiss-Prot/TrEMBL entries against PS00655 • view ligand binding statistics

Matching PDB structures: 1BVW 1GZ1 1HGY 1OC5 ... [ALL]

GLYCOSYL_HYDROL_F6_2, PS00656; Glycosyl hydrolases family 6 signature 2  (PATTERN)

Consensus pattern: [LIVMYA]-[LIVA]-[LIVT]-[LIV]-E-P-D-[SAL]-[LI]-[PSAG] D is an active site residue Sequences known to belong to this class detected by the pattern: ALL Other sequence(s) detected in Swiss-Prot: NONE.

• Retrieve an alignment of 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 tree view of all Swiss-Prot/TrEMBL entries matching PS00656 • Retrieve a list of all Swiss-Prot/TrEMBL entries matching PS00656 • Scan Swiss-Prot/TrEMBL entries against PS00656 • view ligand binding statistics

Matching PDB structures: 1BVW 1CB2 1DYS 1GZ1 ... [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	Rouvinen J., Bergfors T., Teeri T.T., Knowles J.K., Jones T.A.
	Title	Three-dimensional structure of cellobiohydrolase II from Trichoderma reesei.
	Source	Science 249:380-386(1990).
	PubMed ID	2377893

6	Authors	Gilkes N.R., Claeyssens M., Aebersold R., Henrissat B., Meinke A., Morrison H.D., Kilburn D.G., Warren R.A.J., Miller R.C. Jr.
	Title	Structural and functional relationships in two families of beta-1,4-glycanases.
	Source	Eur. J. Biochem. 202:367-377(1991).
	PubMed ID	1761039

E1
Source	http://www.uniprot.org/docs/glycosid

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