Download MendeleyCrystal structure of a bacterial chitinase at 2.3 A resolution.
Perrakis, A., Tews, I., Dauter, Z., Oppenheim, A.B., Chet, I., Wilson, K.S., Vorgias, C.E.(1994) Structure 2: 1169-1180
- PubMed: 7704527
- DOI: https://doi.org/10.1016/s0969-2126(94)00119-7
- Primary Citation of Related Structures:
1CTN - PubMed Abstract:
Chitinases cleave the beta-1-4-glycosidic bond between the N-acetyl-D-glucosamine units of which chitin is comprised. Chitinases are present in plants, bacteria and fungi, but whereas structures are available for two prototypic plant enzymes, no structure is available for a bacterial or fungal chitinase. To redress this imbalance, the structure of native chitinase A from Serratia marcescens has been solved by multiple isomorphous replacement and refined at 2.3 A resolution, resulting in a crystallographic R-factor of 16.2%. The enzyme comprises three domains: an all beta-strand amino-terminal domain, a catalytic alpha/beta-barrel domain, and a small alpha+beta-fold domain. There are several residues with unusual geometries in the structure. Structure determination of chitinase A in complex with N,N',N",N"'-tetra-acetylo-chitotetraose, together with biochemical and sequence analysis data, enabled the positions of the active-site and catalytic residues to be proposed. The reaction mechanism seems to be similar to that of lysozyme and most other glycosylhydrolases, i.e. general acid-base catalysis. The role of the amino-terminal domain could not be identified, but it has similarities to the fibronectin III domain. This domain may possibly facilitate the interaction of chitinase A with chitin.
Organizational Affiliation:
European Molecular Biology Laboratory, Hamburg, Germany.
