Journal
PROTEINS-STRUCTURE FUNCTION AND BIOINFORMATICS
Volume 78, Issue 2, Pages 348-356Publisher
WILEY
DOI: 10.1002/prot.22548
Keywords
debranching enzyme; cyclodextrin/pullulan-hydrolyzing enzyme; crystal structure; neopullulanase; dimerization
Categories
Funding
- Korean government. (MOST) [2007-03850]
- KRIBB Research initiative Program
- National Research Foundation of Korea [2007-03850] Funding Source: Korea Institute of Science & Technology Information (KISTI), National Science & Technology Information Service (NTIS)
Ask authors/readers for more resources
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-angstrom 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. Proteins 2010; 78:348-356. (C) 2009 Wiley-Liss, Inc.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available