Structural Studies of a Two-domain Chitinase from Streptomyces griseus HUT6037Kezuka, Y., Ohishi, M., Itoh, Y., Watanabe, J., Mitsutomi, M., Watanabe, T., Nonaka, T.
(2006) J.Mol.Biol. 358: 472-484
- PubMed: 16516924
- DOI: 10.1016/j.jmb.2006.02.013
- Primary Citation of Related Structures:
- PubMed Abstract:
- A modular family 19 chitinase found in the prokaryotic organism Streptomyces griseus HUT 6037
Ohno, T.,Armand, S.,Hata, T.,Nikaidou, N.,Henrissat, B.,Mitsutomi, M.,Watanabe, T.
(1996) J.Bacteriol. 178: 5065
- Functional analysis of the chitin-binding domain of a family 19 chitinase from Streptomyces griseus HUT6037: substrate-binding affinity and cis-dominant increase of antifungal function
Itoh, Y.,Kawase, T.,Nikaidou, N.,Fukada, H.,Mitsutomi, M.,Watanabe, T.,Itoh, Y.
(2002) Biosci.Biotechnol.Biochem. 66: 1084
- Family 19 chitinases of Streptomyces species: characterization and distribution
Watanabe, T.,Kanai, R.,Kawase, T.,Tanabe, T.,Mitsutomi, M.,Sakuda, S.,Miyashita, K.
(1999) Microbiology 145: 3353
Chitinase C (ChiC) from Streptomyces griseus HUT6037 was the first glycoside hydrolase family 19 chitinase that was found in an organism other than higher plants. An N-terminal chitin-binding domain and a C-terminal catalytic domain connected by a li ...
Chitinase C (ChiC) from Streptomyces griseus HUT6037 was the first glycoside hydrolase family 19 chitinase that was found in an organism other than higher plants. An N-terminal chitin-binding domain and a C-terminal catalytic domain connected by a linker peptide constitute ChiC. We determined the crystal structure of full-length ChiC, which is the only representative of the two-domain chitinases in the family. The catalytic domain has an alpha-helix-rich fold with a deep cleft containing a catalytic site, and lacks three loops on the domain surface compared with the catalytic domain of plant chitinases. The chitin-binding domain is an all-beta protein with two tryptophan residues (Trp59 and Trp60) aligned on the surface. We suggest the binding mechanism of tri-N-acetylchitotriose onto the chitin-binding domain on the basis of molecular dynamics (MD) simulations. In this mechanism, the ligand molecule binds well on the surface-exposed binding site through two stacking interactions and two hydrogen bonds and only Trp59 and Trp60 are involved in the binding. Furthermore, the flexibility of the Trp60 side-chain, which may be involved in adjusting the binding surface to fit the surface of crystalline chitin by the rotation of chi2 angle, is shown.
Department of BioEngineering, Nagaoka University of Technology, Nagaoka, Niigata 940-2188, Japan.