1ogo
From Proteopedia
DEX49A FROM PENICILLIUM MINIOLUTEUM COMPLEX WITH ISOMALTOSE
Overview
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.
About this Structure
1OGO is a Single protein structure of sequence from Penicillium minioluteum. Full crystallographic information is available from OCA.
Reference
Dextranase from Penicillium minioluteum: reaction course, crystal structure, and product complex., Larsson AM, Andersson R, Stahlberg J, Kenne L, Jones TA, Structure. 2003 Sep;11(9):1111-21. PMID:12962629 Page seeded by OCA on Sat May 3 03:49:18 2008
