{PDOC00510}
{PS00591; GH10_1}
{PS51760; GH10_2}
{BEGIN}
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* Glycosyl hydrolases family 10 (GH10) active site and domain profile *
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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 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 <PDB:1R85>)
[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
{END}