1QVB

CRYSTAL STRUCTURE OF THE BETA-GLYCOSIDASE FROM THE HYPERTHERMOPHILE THERMOSPHAERA AGGREGANS

Summary for 1QVB

• Entry DOI: 10.2210/pdb1qvb/pdb
• Descriptor: BETA-GLYCOSIDASE (2 entities in total)
• Functional Keywords: tim-barrel, thermostable, hydrolase
• Biological source: Thermosphaera aggregans
• Total number of polymer chains: 2
• Total formula weight: 111005.70

Authors

Chi, Y.-I.,Martinez-Cruz, L.A.,Swanson, R.V.,Robertson, D.E.,Kim, S.-H. (deposition date: 1999-07-07, release date: 1999-07-13, Last modification date: 2024-02-14)

Primary citation

Chi, Y.I.,Martinez-Cruz, L.A.,Jancarik, J.,Swanson, R.V.,Robertson, D.E.,Kim, S.H.
Crystal structure of the beta-glycosidase from the hyperthermophile Thermosphaera aggregans: insights into its activity and thermostability.
FEBS Lett., 445:375-383, 1999

PubMed 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.

PubMed: 10094493
DOI: 10.1016/S0014-5793(99)00090-3

Experimental method

X-RAY DIFFRACTION (2.4 Å)