Crystal structure of the β‐glycosidase from the hyperthermophileThermosphaera aggregans: insights into its activity and thermostability
- 26 February 1999
- journal article
- Published by Wiley in FEBS Letters
- Vol. 445 (2-3), 375-383
- https://doi.org/10.1016/s0014-5793(99)00090-3
Abstract
The glycosyl hydrolases are an important group of enzymes that are responsible for cleaving a range of biologically significant carbohydrate compounds. Structural information on these enzymes has provided useful information on their molecular basis for the functional variations, while the characterization of the structural features that account for the high thermostability of proteins is of great scientific and biotechnological interest. To these ends we have determined the crystal structure of the beta-glycosidase from a hyperthermophilic archeon Thermosphaera aggregans. The structure is a (beta/alpha)8 barrel (TIM-barrel), as seen in other glycosyl hydrolase family 1 members, and forms a tetramer. Inspection of the active site and the surrounding area reveals two catalytic glutamate residues consistent with the retaining mechanism and the surrounding polar and aromatic residues consistent with a monosaccharide binding site. Comparison of this structure with its mesophilic counterparts implicates a variety of structural features that could contribute to the thermostability. These include an increased number of surface ion pairs, an increased number of internal water molecules and a decreased surface area upon forming an oligomeric quaternary structure.Keywords
This publication has 40 references indexed in Scilit:
- Sulfur-inhibited Thermosphaera aggregans sp. nov., a new genus of hyperthermophilic archaea isolated after its prediction from environmentally derived 16S rRNA sequencesInternational Journal of Systematic and Evolutionary Microbiology, 1998
- Crystal structure of the β-glycosidase from the hyperthermophilic archeon Sulfolobus solfataricus: resilience as a key factor in thermostabilityJournal of Molecular Biology, 1997
- Comparison of a β-Glucosidase and a β-Mannosidase from the Hyperthermophilic Archaeon Pyrococcus furiosusJournal of Biological Chemistry, 1996
- Analysis of protein conformational characteristics related to thermostabilityProtein Engineering, Design and Selection, 1996
- Structures and mechanisms of glycosyl hydrolasesStructure, 1995
- Isolation of a hyperthermophilic archaeum predicted by in situ RNA analysisNature, 1995
- β‐Glucosidase, β‐galactosidase, family A cellulases, family F xylanases and two barley glycanases form a superfamily of enzymes wit 8‐fold β/α architecture and with two conserved glutamates near the carboxy‐terminal ends of β‐strands four and sevenFEBS Letters, 1995
- Mechanisms of enzymatic glycoside hydrolysisCurrent Opinion in Structural Biology, 1994
- PROCHECK: a program to check the stereochemical quality of protein structuresJournal of Applied Crystallography, 1993
- Catalytic mechanism of enzymic glycosyl transferChemical Reviews, 1990