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A novel chitin‐binding mode of the chitin‐binding domain of chitinase A1 from Bacillus circulans WL ‐12 revealed by solid‐state NMR
Author(s) -
Tanaka Hiroki,
Akutsu Hideo,
Yabuta Izumi,
Hara Masashi,
Sugimoto Hayuki,
Ikegami Takahisa,
Watanabe Takeshi,
Fujiwara Toshimichi
Publication year - 2018
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1002/1873-3468.13226
Subject(s) - chitin , bacillus circulans , chitinase , chemistry , binding site , binding domain , stereochemistry , biochemistry , crystallography , chitosan , enzyme
Chitin‐binding domain of chitinase A1 (Ch BD C hiA1 ) is characteristic because it binds only to insoluble crystalline chitin. While binding sites of major carbohydrate‐binding modules carry multiple aromatic rings aligned on a surface, lethal mutations for Ch BD C hiA1 were reported only at W687, a location completely different from the site mentioned above, in spite of their similar main‐chain folds. Here, the structural mechanism underlying its crystalline chitin binding was uncovered by solid‐state NMR . Based on 13 C‐ and 15 N‐signal assignment of microcrystalline Ch BD C hiA1 , the chemical shift perturbation on chitin binding was carefully examined. The perturbation was greatest at W687 and nonaromatic residues surrounding it, revealing their direct involvement in chitin binding. These residues and Q679 should provide a novel chitin‐binding platform parallel to the W687 ring.