Atomic resolution of the crystal structure of the hyperthermophilic family 12 endocellulase and stabilizing role of the DxDxDG calcium-binding motif in Pyrococcus furiosus.
Hyperthermophilic glycoside hydrolase family 12 endocellulase (EGPf) from the archaeon Pyrococcus furiosus catalyzes the hydrolytic cleavage of β-1,4-glucosidic linkage in β-glucan cellulose. A truncated EGPf (EGPfΔN30) mutant lacking the proline and hydroxyl-residue rich region at the N terminus was constructed, and its crystal structure was resolved at an atomic resolution of 1.07 Å. Our results indicate that the structure of EGPf, which consists of a β-jelly roll, exhibits structural similarity with the endocellulase of Thermotoga maritima. Additionally, we further determined that the thermostability of EGPf is maintained in part by the binding of Ca²⁺ in a DxDxDG Ca²⁺-binding motif, atypical of most archaeal proteins.
National Institute of Advanced Industrial Science and Technology, Biomass Technology Research Center, 3-11-32 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-0046, Japan.
SourceFEBS letters 586:7 2012 Apr 5 pg 1009-13
MeSHAmino Acid Motifs
Calorimetry, Differential Scanning
Pub Type(s)Journal Article