PROSITE documentation PDOC00565
Glycosyl hydrolases family 5 signature


The microbial degradation of cellulose and xylans requires several types of enzymes such as endoglucanases (EC, cellobiohydrolases (EC (exoglucanases), or xylanases (EC [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 A [3] or as the glycosyl hydrolases family 5 [4,E1]. The enzymes which are currently known to belong to this family are listed below.

  • Endoglucanases from various species and strains of Bacillus.
  • Butyrivibrio fibrisolvens endoglucanases 1 (end1) and A (celA).
  • Caldocellum saccharolyticum bifunctional endoglucanase/exoglucanase (celB). This protein consists of two domains; it is the C-terminal domain, which has endoglucanase activity, which belongs to this family.
  • Clostridium acetobutylicum endoglucanase (eglA).
  • Clostridium cellulolyticum endoglucanases A (celccA) and D (celccD).
  • Clostridium cellulovorans endoglucanase B (engB) and D (engD).
  • Clostridium thermocellum endoglucanases B (celB), C (celC), E (celE), G (celG) and H (celH).
  • Erwinia chrysanthemi endoglucanase Z (celZ).
  • Fibrobacter succinogenes endoglucanase 3 (cel-3).
  • Pseudomonas fluorescens endoglucanase C (celC).
  • Pseudomonas solanacearum endoglucanase (egl).
  • Robillarda strain Y-20 endoglucanase I.
  • Ruminococcus albus endoglucanases I (EG-I), A (celA), and B (celB).
  • Ruminococcus flavefaciens cellodextrinase A (celA).
  • Ruminococcus flavefaciens endoglucanase E (celE).
  • Streptomyces lividans endoglucanase.
  • Thermomonospora fusca endoglucanase E-5 (celE).
  • Trichoderma reesei endoglucanase II (EGLII).
  • Xanthomonas campestris endoglucanase (engxcA).

As well as:

  • Baker's yeast glucan 1,3-β-glucosidase I/II (EC (EXG1).
  • Baker's yeast glucan 1,3-β-glucosidase 2 (EC (EXG2).
  • Baker's yeast sporulation-specific glucan 1,3-β-glucosidase (SPR1).
  • Caldocellum saccharolyticum β-mannanase (EC (manA).
  • Yeast hypothetical protein YBR056w.
  • Yeast hypothetical protein YIR007w.

One of the conserved regions in these enzymes contains a conserved glutamic acid residue which is potentially involved [5] in the catalytic mechanism. We use this region as a signature pattern.

Expert(s) to contact by email:

Henrissat B.

Last update:

December 2004 / Pattern and text revised.


Technical section

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

GLYCOSYL_HYDROL_F5, PS00659; Glycosyl hydrolases family 5 signature  (PATTERN)


1AuthorsBeguin P.
TitleMolecular biology of cellulose degradation.
SourceAnnu. Rev. Microbiol. 44:219-248(1990).
PubMed ID2252383

2AuthorsGilkes N.R. Henrissat B. Kilburn D.G. Miller R.C. Jr. Warren R.A.J.
TitleDomains in microbial beta-1, 4-glycanases: sequence conservation, function, and enzyme families.
SourceMicrobiol. Rev. 55:303-315(1991).
PubMed ID1886523

3AuthorsHenrissat B. Claeyssens M. Tomme P. Lemesle L. Mornon J.-P.
TitleCellulase families revealed by hydrophobic cluster analysis.
SourceGene 81:83-95(1989).
PubMed ID2806912

4AuthorsHenrissat B.
TitleA classification of glycosyl hydrolases based on amino acid sequence similarities.
SourceBiochem. J. 280:309-316(1991).
PubMed ID1747104

5AuthorsPy B. Bortoli-German I. Haiech J. Chippaux M. Barras F.
TitleCellulase EGZ of Erwinia chrysanthemi: structural organization and importance of His98 and Glu133 residues for catalysis.
SourceProtein Eng. 4:325-333(1991).
PubMed ID1677466


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