The Unique Branching Patterns of Deinococcus Glycogen Branching Enzymes Are Determined by Their N-Terminal Domains
- 1 March 2009
- journal article
- research article
- Published by American Society for Microbiology in Applied and Environmental Microbiology
- Vol. 75 (5), 1355-1362
- https://doi.org/10.1128/aem.02141-08
Abstract
Glycogen branching enzymes (GBE) or 1,4-alpha-glucan branching enzymes (EC 2.4.1.18) introduce alpha-1,6 branching points in alpha-glucans, e.g., glycogen. To identify structural features in GBEs that determine their branching pattern specificity, the Deinococcus geothermalis and Deinococcus radiodurans GBE (GBE(Dg) and GBE(Dr), respectively) were characterized. Compared to other GBEs described to date, these Deinococcus GBEs display unique branching patterns, both transferring relatively short side chains. In spite of their high amino acid sequence similarity (88%) the D. geothermalis enzyme had highest activity on amylose while the D. radiodurans enzyme preferred amylopectin. The side chain distributions of the products were clearly different: GBE(Dg) transferred a larger number of smaller side chains; specifically, DP5 chains corresponded to 10% of the total amount of transferred chains, versus 6.5% for GBE(Dr). GH13-type GBEs are composed of a central (beta/alpha) barrel catalytic domain and an N-terminal and a C-terminal domain. Characterization of hybrid Deinococcus GBEs revealed that the N2 modules of the N domains largely determined substrate specificity and the product branching pattern. The N2 module has recently been annotated as a carbohydrate binding module (CBM48). It appears likely that the distance between the sugar binding subsites in the active site and the CBM48 subdomain determines the average lengths of side chains transferred.Keywords
This publication has 43 references indexed in Scilit:
- Oligosaccharide recognition and binding to the carbohydrate binding module of AMP‐activated protein kinaseFEBS Letters, 2007
- The evolution of putative starch‐binding domainsFEBS Letters, 2006
- A Novel Branching Enzyme of the GH-57 Family in the Hyperthermophilic Archaeon Thermococcus kodakaraensis KOD1Journal of Bacteriology, 2006
- Crystal Structure of Pullulanase: Evidence for Parallel Binding of Oligosaccharides in the Active SiteJournal of Molecular Biology, 2006
- Crystal Structure of Maltooligosyltrehalose Trehalohydrolase from Deinococcus radiodurans in Complex with DisaccharidesJournal of Molecular Biology, 2005
- Relationship of sequence and structure to specificity in the α-amylase family of enzymesBiochimica et Biophysica Acta (BBA) - Protein Structure and Molecular Enzymology, 2001
- Crystal structure of glycosyltrehalose trehalohydrolase from the hyperthermophilic archaeum Sulfolobus solfataricus 1 1Edited by D. ReesJournal of Molecular Biology, 2000
- Three-dimensional structure of Pseudomonas isoamylase at 2.2 Å resolution 1 1Edited by R. HuberJournal of Molecular Biology, 1998
- Nucleotide Sequence and X-ray Structure of Cyclodextrin Glycosyltransferase from Bacillus circulans Strain 251 in a Maltose-dependent Crystal FormJournal of Molecular Biology, 1994
- Biosynthesis of bacterial glycogen. Purification and properties of the Escherichia coli B α-1,4-glucan:α-1,4-glucan 6-glycosyltransferaseBiochemistry, 1977