3A4X

Crystal structures of catalytic site mutants of active domain 2 of thermostable chitinase from Pyrococcus furiosus complexed with chito-oligosaccharides

Summary for 3A4X

• Entry DOI: 10.2210/pdb3a4x/pdb
• Related: 3A4W 3AFB
• Descriptor: Chitinase, 2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-alpha-D-glucopyranose, MAGNESIUM ION, ... (6 entities in total)
• Functional Keywords: archaea, chitinase, glycosyl hydrolase, hydrolase
• Biological source: Pyrococcus furiosus
• Total number of polymer chains: 2
• Total formula weight: 71707.14

Authors

Tsuji, H.,Nishimura, S.,Inui, T.,Ishikawa, K.,Nakamura, T.,Uegaki, K. (deposition date: 2009-07-22, release date: 2010-06-09, Last modification date: 2023-11-01)

Primary citation

Tsuji, H.,Nishimura, S.,Inui, T.,Kado, Y.,Ishikawa, K.,Nakamura, T.,Uegaki, K.
Kinetic and crystallographic analyses of the catalytic domain of chitinase from Pyrococcus furiosus- the role of conserved residues in the active site
Febs J., 277:2683-2695, 2010

PubMed Abstract: The hyperthermostable chitinase from the hyperthermophilic archaeon Pyrococcus furiosus has a unique multidomain structure containing two chitin-binding domains and two catalytic domains, and exhibits strong crystalline chitin hydrolyzing activity at high temperature. In order to investigate the structure-function relationship of this chitinase, we analyzed one of the catalytic domains (AD2) using mutational and kinetic approaches, and determined the crystal structure of AD2 complexed with chito-oligosaccharide substrate. Kinetic studies showed that, among the acidic residues in the signature sequence of family 18 chitinases (DXDXE motif), the second Asp (D(2)) and Glu (E) residues play critical roles in the catalysis of archaeal chitinase. Crystallographic analyses showed that the side-chain of the catalytic proton-donating E residue is restrained into the favorable conformer for proton donation by a hydrogen bond interaction with the adjacent D(2) residue. The comparison of active site conformations of family 18 chitinases provides a new criterion for the subclassification of family 18 chitinase based on the conformational change of the D(2) residue.

PubMed: 20553502
DOI: 10.1111/j.1742-464X.2010.07685.x

Experimental method

X-RAY DIFFRACTION (1.76 Å)