Skip to main content
SLU publication database (SLUpub)

Research article2003Peer reviewedOpen access

Dextranase from Penicillum minioluteum: Reaction course, crystal structure, and product complex

Larsson AM, Andersson R, Stahlberg J, Kenne L, Jones TA


Dextranase catalyzes the hydrolysis of the alpha-1,6-glycosidic linkage in dextran polymers. The structure of dextranase, Dex49A, from Penicillium, minioluteum was solved in the apo-enzyme and product-bound forms. The main domain of the enzyme is a right-handed parallel beta helix, which is connected to a beta sandwich domain at the N terminus. In the structure of the product complex, isomaltose was found to bind in a crevice on the surface of the enzyme. The glycosidic oxygen of the glucose unit in subsite +1 forms a hydrogen bond to the suggested catalytic acid, Asp395. By NMR spectroscopy the reaction course was shown to occur with net inversion at the anomeric carbon, implying a single displacement mechanism. Both Asp376 and Asp396 are suitably positioned to activate the water molecule that performs the nucleophilic attack. A new clan that links glycoside hydrolase families 28 and 49 is suggested

Published in

2003, Volume: 11, number: 9, pages: 1111-1121
Publisher: CELL PRESS

      SLU Authors

        • Ståhlberg, Jerry

          • Department of Molecular Biology, Swedish University of Agricultural Sciences

        Publication identifier


        Permanent link to this page (URI)