{PDOC00415} {PS00502; POLYGALACTURONASE} {BEGIN} ********************************* * Polygalacturonase active site * ********************************* Polygalacturonase (EC 3.2.1.15) (PG) (pectinase) [1,2] catalyzes the random hydrolysis of 1,4-alpha-D-galactosiduronic linkages in pectate and other galacturonans. In fruit, polygalacturonase plays an important role in cell wall metabolism during ripening. In plant bacterial pathogens such as Erwinia carotovora or Pseudomonas solanacearum and fungal pathogens such as Aspergillus niger, polygalacturonase is involved in maceration and soft- rotting of plant tissue. Exo-poly-alpha-D-galacturonosidase (EC 3.2.1.82) (exoPG) [3] hydrolyzes peptic acid from the non-reducing end, releasing digalacturonate. Prokaryotic, eukaryotic PG and exoPG share a few regions of sequence similarity. We selected the best conserved of these regions, which is centered on a conserved histidine most probably involved in the catalytic mechanism [4]. -Consensus pattern: [GSDENKRH]-x(2)-[VMFC]-x(2)-[GS]-H-G-[LIVMAG]-x(1,2)- [LIVM]-G-S [H may be the active site residue] -Sequences known to belong to this class detected by the pattern: ALL. -Other sequence(s) detected in Swiss-Prot: NONE. -Note: These proteins belong to family 28 in the classification of glycosyl hydrolases [5,E1]. -Last update: May 2004 / Text revised. [ 1] Ruttowski E., Labitzke R., Khanh N.Q., Loeffler F., Gottschalk M., Jany K.-D. Biochim. Biophys. Acta 1087:104-106(1990). [ 2] Huang J.H., Schell M.A. "DNA sequence analysis of pglA and mechanism of export of its polygalacturonase product from Pseudomonas solanacearum." J. Bacteriol. 172:3879-3887(1990). PubMed=2193922 [ 3] He S.Y., Collmer A. "Molecular cloning, nucleotide sequence, and marker exchange mutagenesis of the exo-poly-alpha-D-galacturonosidase-encoding pehX gene of Erwinia chrysanthemi EC16." J. Bacteriol. 172:4988-4995(1990). PubMed=2168372 [ 4] Bussink H.J.D., Buxton F.P., Visser J. "Expression and sequence comparison of the Aspergillus niger and Aspergillus tubigensis genes encoding polygalacturonase II." Curr. Genet. 19:467-474(1991). PubMed=1878999 [ 5] Henrissat B. "A classification of glycosyl hydrolases based on amino acid sequence similarities." Biochem. J. 280:309-316(1991). PubMed=1747104 [E1] https://www.uniprot.org/docs/glycosid -------------------------------------------------------------------------------- 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}