Structural Analysis of 4-α-Glucanotransferase from Pyrococcus Furiosus

Abstract

4-α-Glucanotransferase, an enzyme from Pyrococcus furiosus, catalyzes the hydrolysis of a glucose unit from a donor molecule, and transfers it to an acceptor molecule. The sequence of this enzyme is very much similar to 4-α-Glucanotransferase from Thermococcus litoralis. The donor and acceptor molecules are carbohydrates of varying length. The donor and acceptor sites are present within the enzyme only. The donor site is present in domain-I having catalytic residues Glutamate-124 and Aspartate-215, working in a acid-base catalysis kind of mechanism, similar in case of the enzyme from Thermococcus litoralis. The acceptor site is present in domain-II having interacting residues Histidine-369 and Arginine-372. The function of domain-III is not yet known.