Reaction: [(1→4)-α-D-galacturonosyl]n + H2O = α-D-galacturonosyl-(1→4)-D-galacturonate + [(1→4)-α-D-galacturonosyl]n-2
Other name(s): pehX (gene name); poly(1,4-α-D-galactosiduronate) digalacturonohydrolase; exopolygalacturonosidase (misleading); poly[(1→4)-α-D-galactosiduronate] digalacturonohydrolase; exo-poly-α-galacturonosidase
Systematic name: poly[(1→4)-α-D-galactosiduronate] non-reducing-end-digalacturonohydrolase
Comments: The enzyme, characterized from bacteria, hydrolyses the second α-1,4-glycosidic bond from the non-reducing end of polygalacturonate, releasing digalacturonate.
Links to other databases: BRENDA, EXPASY, ExplorEnz, KEGG, MetaCyc, CAS registry number: 37288-58-7
References:
1. Hasegawa, H. and Nagel, C.W. Isolation of an oligogalacturonate hydrolase from a Bacillus species. Arch. Biochem. Biophys. 124 (1968) 513-520. [PMID: 5661621]
2. Hatanaka, C. and Ozawa, J. Enzymic degradation of pectic acid. XIII. New exopolygalacturonase producing digalacturonic acid from pectic acid. J. Agric. Chem. Soc. Jpn.. 43 (1968) 764-772.
3. Hatanaka, C. and Ozawa, J. Ber. des O'Hara Inst. 15 (1971) 47.
4. He, S.Y. and Collmer, A. Molecular cloning, nucleotide sequence, and marker exchange mutagenesis of the exo-poly-α-D-galacturonosidase-encoding pehX gene of Erwinia chrysanthemi EC16. J. Bacteriol. 172 (1990) 4988-4995. [PMID: 2168372]