Structural features of the Nostoc punctiforme debranching enzyme reveal the basis of its mechanism and substrate specificity

Cited 14 time in scopus
Metadata Downloads
Title
Structural features of the Nostoc punctiforme debranching enzyme reveal the basis of its mechanism and substrate specificity
Author(s)
A B Dumbrepatil; J H Choi; J T Park; M J Kim; Eui-Jeon Woo; K H Park
Bibliographic Citation
Proteins-Structure Function and Bioinformatics, vol. 78, no. 2, pp. 348-356
Publication Year
2010
Abstract
The debranching enzyme Nostoc punctiforme debranching enzyme (NPDE) from the cyanobacterium Nostoc punctiforme (PCC73102) hydrolyzes the alpha-1,6 glycosidic linkages of malto-oligosaccharides. Despite its high homology to cyclodextrin/pullulan (CD/PUL)-hydrolyzing enzymes from glycosyl hydrolase 13 family (GH-13), NPDE exhibits a unique catalytic preference for longer malto-oligosaccharides (>G8), performing hydrolysis without the transgylcosylation or CD-hydrolyzing activities of other GH-13 enzymes. To investigate the molecular basis for the property of NPDE, we determined the structure of NPDE at 2.37-A resolution. NPDE lacks the typical N-terminal domain of other CD/PUL-hydrolyzing enzymes and forms an elongated dimer in a head-to-head configuration. The unique orientation of residues 25-55 in NPDE yields an extended substrate binding groove from the catalytic center to the dimeric interface. The substrate binding groove with a lengthy cavity beyond the -1 subsite exhibits a suitable architecture for binding longer malto-oligosaccharides (>G8). These structural results may provide a molecular basis for the substrate specificity and catalytic function of this cyanobacterial enzyme, distinguishing it from the classical neopullulanases and CD/PUL-hydrolyzing enzymes.
Keyword
Crystal structureCyclodextrin/pullulan-hydrolyzing enzymeDebranching enzymeDimerizationNeopullulanase
ISSN
0887-3585
Publisher
Wiley
DOI
http://dx.doi.org/10.1002/prot.22548
Type
Article
Appears in Collections:
Division of Biomedical Research > Disease Target Structure Research Center > 1. Journal Articles
Files in This Item:
  • There are no files associated with this item.


Items in OpenAccess@KRIBB are protected by copyright, with all rights reserved, unless otherwise indicated.