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- *********************************
- * 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: [GSDNKRH]-x(2)-[MFC]-x(2)-G-H-G-[LIVMAG]-x(1,2)-[LIVM]-G-S
- [H is the putative 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].
-
- -Last update: June 1994 / Pattern and 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., Schell M.A.
- J. Bacteriol. 172:3879-3887(1990).
- [ 3] He S.Y., Collmer A.
- J. Bacteriol. 172:4988-4995(1990).
- [ 4] Bussink H.J.D., Buxton F.P., Visser J.
- Curr. Genet. 19:467-474(1991).
- [ 5] Henrissat B.
- Biochem. J. 280:309-316(1991).
-