Publication Abstract from PubMed
The structure of jack bean chitinase was solved at 1.8 A resolution by molecular replacement. It is an alpha-helical protein with three disulfide bridges. The active site is related in structure to animal and viral lysozymes. However, unlike in lysozyme, the architecture of the active site suggests a single-step cleavage. According to this mechanism, Glu68 is the proton donor and Glu90 assists in the reaction by moving towards the substrate and recruiting a water molecule that acts as the nucleophile. In this model, a water molecule was found in contact with Glu90 O(epsilon1) and Thr119 O(gamma) at a distance of 3.0 and 2.8 A, respectively. The model is in accordance with the observed inversion mechanism.
Structure of jack bean chitinase.,Hahn M, Hennig M, Schlesier B, Hohne W Acta Crystallogr D Biol Crystallogr. 2000 Sep;56(Pt 9):1096-9. PMID:10957628[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
