{PDOC00510} {PS00591; GH10_1} {PS51760; GH10_2} {BEGIN} *********************************************************************** * Glycosyl hydrolases family 10 (GH10) active site and domain profile * *********************************************************************** 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 F [3] or as the glycosyl hydrolases family 10 (GH10) [4,E1,E2]. All family 10 xylanases hydrolyze the glycosidic bond in a double-displacement 'retaining' mechanism using two catalytic acidic residues, where one residue acts a nucleophile (base) and the other acts as a general acid/base [6.7]. The enzymes which are currently known to belong to this family are listed below. - Aspergillus awamori xylanase A (xynA). - Bacillus sp. strain 125 xylanase (xynA). - Bacillus stearothermophilus xylanase. - Butyrivibrio fibrisolvens xylanases A (xynA) and B (xynB). - Caldocellum saccharolyticum bifunctional endoglucanase/exoglucanase (celB). This protein consists of two domains; it is the N-terminal domain, which has exoglucanase activity, which belongs to this family. - Caldocellum saccharolyticum xylanase A (xynA). - Caldocellum saccharolyticum ORF4. This hypothetical protein is encoded in the xynABC operon and is probably a xylanase. - Cellulomonas fimi exoglucanase/xylanase (cex). - Clostridium stercorarium thermostable celloxylanase. - Clostridium thermocellum xylanases Y (xynY) and Z (xynZ). - Cryptococcus albidus xylanase. - Penicillium chrysogenum xylanase (gene xylP). - Pseudomonas fluorescens xylanases A (xynA) and B (xynB). - Ruminococcus flavefaciens bifunctional xylanase XYLA (xynA). This protein consists of three domains: a N-terminal xylanase catalytic domain that belongs to family 11 of glycosyl hydrolases; a central domain composed of short repeats of Gln, Asn an Trp, and a C-terminal xylanase catalytic domain that belongs to family 10 of glycosyl hydrolases. - Streptomyces lividans xylanase A (xlnA). - Thermoanaerobacter saccharolyticum endoxylanase A (xynA). - Thermoascus aurantiacus xylanase. - Thermophilic bacterium Rt8.B4 xylanase (xynA). The overall structure of the GH10 domain corresponds to an eightfold alpha/ beta-barrel (TIM-barrel) with a typical deep groove in the centre, allowing an 'endo' type of action on the large polysaccharide backbone (see ) [6,7]. One of the conserved regions in these enzymes is centered on a conserved glutamic acid residue which has been shown [5], in the exoglucanase from Cellulomonas fimi, to be directly involved in glycosidic bond cleavage by acting as a nucleophile. We have used this region as a signature pattern. We have also developed a profile that covers the entire GH10 domain. -Consensus pattern: [GTA]-{QNAG}-{GSV}-[LIVN]-x-[IVMF]-[ST]-E-[LIY]-[DN]- [LIVMF] [E is the active site residue] -Sequences known to belong to this class detected by the pattern: ALL, except for Thermoascus aurantiacus xylanase whose sequence seems to be incorrect. -Other sequence(s) detected in Swiss-Prot: 16. -Sequences known to belong to this class detected by the profile: ALL. -Other sequence(s) detected in Swiss-Prot: NONE. -Expert(s) to contact by email: Henrissat B.; bernie@afmb.cnrs-mrs.fr -Last update: June 2015 / Text revised; profile added. [ 1] Beguin P. "Molecular biology of cellulose degradation." Annu. Rev. Microbiol. 44:219-248(1990). PubMed=2252383; DOI=10.1146/annurev.mi.44.100190.001251 [ 2] Gilkes N.R., Henrissat B., Kilburn D.G., Miller R.C. Jr., Warren R.A.J. "Domains in microbial beta-1, 4-glycanases: sequence conservation, function, and enzyme families." Microbiol. Rev. 55:303-315(1991). PubMed=1886523 [ 3] Henrissat B., Claeyssens M., Tomme P., Lemesle L., Mornon J.-P. "Cellulase families revealed by hydrophobic cluster analysis." Gene 81:83-95(1989). PubMed=2806912 [ 4] Henrissat B. "A classification of glycosyl hydrolases based on amino acid sequence similarities." Biochem. J. 280:309-316(1991). PubMed=1747104 [ 5] Tull D., Withers S.G., Gilkes N.R., Kilburn D.G., Warren R.A.J., Aebersold R. "Glutamic acid 274 is the nucleophile in the active site of a 'retaining' exoglucanase from Cellulomonas fimi." J. Biol. Chem. 266:15621-15625(1991). PubMed=1678739 [ 6] Solomon V., Teplitsky A., Shulami S., Zolotnitsky G., Shoham Y., Shoham G. "Structure-specificity relationships of an intracellular xylanase from Geobacillus stearothermophilus." Acta Crystallogr. D 63:845-859(2007). PubMed=17642511; DOI=10.1107/S0907444907024845 [ 7] Han X., Gao J., Shang N., Huang C.-H., Ko T.-P., Chen C.-C., Chan H.-C., Cheng Y.-S., Zhu Z., Wiegel J., Luo W., Guo R.-T., Ma Y. "Structural and functional analyses of catalytic domain of GH10 xylanase from Thermoanaerobacterium saccharolyticum JW/SL-YS485." Proteins 81:1256-1265(2013). PubMed=23508990; DOI=10.1002/prot.24286 [E1] https://www.uniprot.org/docs/glycosid [E2] http://www.cazy.org/GH10.html -------------------------------------------------------------------------------- PROSITE is copyrighted by the SIB Swiss Institute of Bioinformatics and distributed under the Creative Commons Attribution-NonCommercial-NoDerivatives (CC BY-NC-ND 4.0) License, see https://prosite.expasy.org/prosite_license.html -------------------------------------------------------------------------------- {END}