Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.2.1.15 (pectinase)
 2,440 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The endopolygalacturonase (EC 3.2.1.15) enzyme produced in vitro by Sclerotinia sclerotiorum were found to consist of numerous isoforms covering a broad pI range. Two of the isoforms, labelled PG2 and PG3, were purified using gel-filtration chromatography, isoelectric focusing and anion-exchange chromatography. The pIs of PG2 and PG3 were, respectively, 4.8 and 4.9. Their molecular weights were similar. Both enzymes hydrolysed 0.9% of the bonds in reaching a 50% reduction in viscosity. However, their enzymic parameters were different. Their amino acid compositions differed only in the aspartic acid-asparagine content. The N-terminal sequences differed at the fourth amino acid only. PG2 and PG3 exhibited a high level of glycosylation compared to a similar enzyme isolated from Aspergillus niger. Antibody raised against PG3 was shown to crossreact with PG2, but not with the enzyme purified from Aspergillus niger.
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PMID:Purification and characterization of two endopolygalacturonases from Sclerotinia sclerotiorum. 199 Nov 45

A polygalacturonase (PG)-encoding gene from Saccharomyces cerevisiae (PGU1) was successfully expressed in the methylotrophic yeast Pichia pastoris. PG secretion was efficiently directed by the S. cerevisiae alpha-factor signal sequence, while the native (PGU1) leader peptide was unable to direct protein export in P. pastoris. The level of PGU1 activity achieved in P. pastoris was significantly enhanced when compared to activity using the same gene in S. cerevisiae. Expression of PG proteins, engineered by site-directed mutagenesis, in P. pastoris showed that aspartic acid residues at positions 179, 200, and 201, and histidine 222 were essential for enzyme activity. Mutation of the two potential glycosylation sites in PGU1 showed that the two residues individually (N318D, N330D) did not affect secreted enzyme activity, but the double mutant caused a 50% reduction in enzyme activity when compared to the wild-type PGU1 transformant.
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PMID:Mutagenesis of key amino acids alters activity of a Saccharomyces cerevisiae endo-polygalacturonase expressed in Pichia pastoris. 1204 73

Abstract The fungal pathogen Botrytis cinerea is capable of developing on a wide variety of host plants that differ greatly in their pH values and biochemical defences. To evaluate whether the pH of the host tissue can regulate the production of pathogenicity factors by this fungus, we examined the ability of two isolates of B. cinerea that originated from different plant species to secrete putative virulence elements on synthetic media buffered at pH 2.0 to pH 7.0. Even though differing in the intensity of their responses, both isolates reacted similarly to their ambient pH. The production of extracellular polysaccharides and oxalic acid was detectable above pH 4.0 and pH 5.0 respectively. Conversely, the production of aspartic acid proteases could only be seen between pH 3.0 and 4.0. Finally, the secretion of polygalacturonase and laccase activity was found to exhibit two maxima, one around pH 3.1 and one around pH 6.0. Thus, pathogenicity factor production was found to be minimal between pH 4.5 and 5.5 and a different set of factors was produced at pH 3.1 and 6.0, two values that were found to correspond respectively to the average host fruit and leaf pH. These results demonstrate that ambient pH differentially regulates the synthesis of pathogenicity factors by Botrytis and may act as a novel regulatory element to assist this fungus in tuning its virulence machinery to the composition of its host tissue.
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PMID:Differential regulation by ambient pH of putative virulence factor secretion by the phytopathogenic fungus Botrytis cinerea. 1971 67