{PDOC52008}
{PS52008; GH81}
{BEGIN}
*******************************************************
* Glycosyl hydrolases family 81 (GH81) domain profile *
*******************************************************

Glycoside hydrolases (GHs, EC 3.2.1.-) form a widespread group of enzymes that
hydrolyze the  glycoside  bond  between  monosaccharide  units  or  between  a
carbohydrate and  an aglycone moiety. GHs can act specifically as exo-cleaving
enzymes to  remove  the  sugar units from the ends of chains and release small
sugar products,  or  endo-cleaving  enzymes  to  act within the polysaccharide
chain and  produce oligosaccharides. The GH family 81 (GH81) includes proteins
with endo-beta-1,3-glucanase  widely  distributed  in plants, fungi, bacteria,
archaea and  viruses.  GH81  proteins show rather diverse physiological roles.
These proteins  share  a  common  region  of  around  650  amino acids that is
characteristic of the family [1,2,3,4].

The core  catalytic  domain  of  family 81 GHs consists of an N-terminal beta-
sandwich subdomain,   a  C-terminal  (alpha/beta)6  barrel  subdomain  and  an
additional alpha/beta-subdomain  between  them  (see  <PDB:4K3A>).  The  beta-
sandwich subdomain  compacts  with  (alpha/beta)6 barrel subdomain and forms a
long binding  cleft.  Along the catalytic cleft there are a number of aromatic
residues that  are conserved in GH family 81 glucanases and may be involved in
stacking interactions   with  the  rings  of  the  glucosyl  residues  of  the
substrate. Three  amino  acid  residues  that are conserved in the family have
been proposed  as  candidate  catalytic residues: an aspartate (acid catalyst)
and two  glutamates  (proton  donor  and  basic  catalyst respectively). These
residues are  located  in  the  base  of  the catalytic cleft present near the
center of the (alpha/beta)6 barrel [2,3,4].

Some proteins known to contain a GH81 domain are listed below:

 - Schizosaccharomyces pombe beta-1,3-Endoglucanase (SpEng1), an extracellular
   protein that  plays  a  critical  role  in  cell  cycle  by  helping in the
   dissolution of the septum.
 - Schizosaccharomyces pombe beta-1,3-endoglucanase (SpEng2), an intracellular
   cytoplasmic protein involved in actin assembly.
 - Saccharomyces   cerevisiae  ScEng1,  an  extracellular  protein  that  acts
   together with  the  Cts1  chitinase during cell separation to hydrolyze the
   cell wall components of the septum.
 - Saccharomyces cerevisiae ScEng2, an intracellular cytoplasmic protein.
 - Candida  albicans  beta-1,3-endoglucanase  (CAENG1),  involved in cell wall
   separation.
 - Pneumocystis  sp.  beta-1,3-endoglucanase,  regulates cell-wall beta-glucan
   processing during its life cycle.
 - Rhizomucor miehei RmLam81A.
 - Plant  beta-glucan-elicitor-binding-proteins  (GBPs) that are usually found
   in the  plasma membrane and are pasrt of a defense mechanism against fungal
   infection.
 - Paenibacillus sp. beta-1,3-glucanas LamA.
 - Clostridium thermocellum Eng1 (CtLam81A), a beta-1,3-glucanase belonging to
   cellulosomal complex.

The profile we developed covers the whole GH81 domain.

-Sequences known to belong to this class detected by the profile: ALL.
-Other sequence(s) detected in Swiss-Prot: NONE.
-Last update: October 2022 / First entry.

[ 1] Martin-Cuadrado A.-B., Fontaine T., Esteban P.-F., del Dedo J.E.,
     de Medina-Redondo M., del Rey F., Latge J.P., Vazquez de Aldana C.R.
     "Characterization of the endo-beta-1,3-glucanase activity of S.
     cerevisiae Eng2 and other members of the GH81 family."
     Fungal. Genet. Biol. 45:542-553(2008).
     PubMed=17933563; DOI=10.1016/j.fgb.2007.09.001
[ 2] Zhou P., Chen Z., Yan Q., Yang S., Hilgenfeld R., Jiang Z.
     "The structure of a glycoside hydrolase family 81
     endo-beta-1,3-glucanase."
     Acta Crystallogr. D. Biol. Crystallogr. 69:2027-2038(2013).
     PubMed=24100321; DOI=10.1107/S090744491301799X
[ 3] Pluvinage B., Fillo A., Massel P., Boraston A.B.
     "Structural Analysis of a Family 81 Glycoside Hydrolase Implicates Its
     Recognition of beta-1,3-Glucan Quaternary Structure."
     Structure 25:1348-1359.e3(2017).
     PubMed=28781080; DOI=10.1016/j.str.2017.06.019
[ 4] Kumar K., Correia M.A.S., Pires V.M.R., Dhillon A., Sharma K.,
     Rajulapati V., Fontes C.M.G.A., Carvalho A.L., Goyal A.
     "Novel insights into the degradation of beta-1,3-glucans by the
     cellulosome of Clostridium thermocellum revealed by structure and
     function studies of a family 81 glycoside hydrolase."
     Int. J. Biol. Macromol. 117:890-901(2018).
     PubMed=29870811; DOI=10.1016/j.ijbiomac.2018.06.003
[E1] http://www.cazy.org/GH81.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}