8BGO

N,N-diacetylchitobiose deacetylase from Pyrococcus chitonophagus with substrate N,N-diacetylchitobiose

Summary for 8BGO

• Entry DOI: 10.2210/pdb8bgo/pdb
• Related: 8BGN 8BGO
• Descriptor: Diacetylchitobiose deacetylase, 2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose, ZINC ION, ... (4 entities in total)
• Functional Keywords: hyperthermophile, hydrolase
• Biological source: Thermococcus chitonophagus
• Total number of polymer chains: 12
• Total formula weight: 383062.78

Authors

Rypniewski, W.,Bejger, M.,Biniek-Antosiak, K. (deposition date: 2022-10-28, release date: 2023-01-11, Last modification date: 2024-02-07)

Primary citation

Biniek-Antosiak, K.,Bejger, M.,Sliwiak, J.,Baranowski, D.,Mohammed, A.S.A.,Svergun, D.I.,Rypniewski, W.
Structural, Thermodynamic and Enzymatic Characterization of N , N -Diacetylchitobiose Deacetylase from Pyrococcus chitonophagus.
Int J Mol Sci, 23:-, 2022

PubMed Abstract: Chitin is a major source of energy and macroelements for many organisms. An important step in its degradation is the deacetylation of chitin or its fragments. Deacetylase from the extremophile has been analyzed by X-ray crystallography, small-angle X-ray scattering, differential scanning calorimetry, isothermal titration calorimetry and NMR to determine its structure, thermodynamics and enzymatic properties. It is a hexameric, zinc-containing metalloenzyme that retains its structural integrity up to temperatures slightly exceeding 100 °C. It removes the acetyl group specifically from the non-reducing end of the sugar substrate. Its main substrate is ,-diacetylchitobiose but it also active, at a reduced level, toward -acetyl-d-glucosamine or a trimer of -acetyl-d-glucosamine units. Crystallographic analysis includes the structure of the enzyme with its main substrate approaching the active site in a monodentate manner, replacing the single water molecule that is bound at the Zn cation when the ligand is absent. The Zn cation remains tetrahedrally coordinated, with three of its ligands provided by the protein's conserved His-Asp-His triad. The crystal structures are consistent with the reaction mechanism proceeding via an anhydride intermediate. Hydrolysis as the first step cannot be ruled out in a hydrated environment but no defined 'hydrolytic water' site can be identified in the analyzed structures.

PubMed: 36555375
DOI: 10.3390/ijms232415736

Experimental method

X-RAY DIFFRACTION (3.08 Å)