| Literature DB >> 16822232 |
Elena S Martens-Uzunova1, Joris S Zandleven, Jaques A E Benen, Hanem Awad, Harrie J Kools, Gerrit Beldman, Alphons G J Voragen, Johan A Van den Berg, Peter J Schaap.
Abstract
The fungus Aspergillus niger is an industrial producer of pectin-degrading enzymes. The recent solving of the genomic sequence of A. niger allowed an inventory of the entire genome of the fungus for potential carbohydrate-degrading enzymes. By applying bioinformatics tools, 12 new genes, putatively encoding family 28 glycoside hydrolases, were identified. Seven of the newly discovered genes form a new gene group, which we show to encode exoacting pectinolytic glycoside hydrolases. This group includes four exo-polygalacturonan hydrolases (PGAX, PGXA, PGXB and PGXC) and three putative exo-rhamnogalacturonan hydrolases (RGXA, RGXB and RGXC). Biochemical identification using polygalacturonic acid and xylogalacturonan as substrates demonstrated that indeed PGXB and PGXC act as exo-polygalacturonases, whereas PGXA acts as an exo-xylogalacturonan hydrolase. The expression levels of all 21 genes were assessed by microarray analysis. The results from the present study demonstrate that exo-acting glycoside hydrolases play a prominent role in pectin degradation.Entities:
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Year: 2006 PMID： 16822232 PMCID： PMC1635439 DOI： 10.1042/BJ20060703
Source DB: PubMed Journal: Biochem J ISSN： 0264-6021 Impact factor: 3.857