5Y2C
Crystal structure of Ostrinia furnacalis Group II chitinase catalytic domain 2 E2180L mutant in complex with PENTA-N-ACETYLCHITOOCTAOSE (NAG)5
5Y2C の概要
エントリーDOI | 10.2210/pdb5y2c/pdb |
分子名称 | insect group II chitinase, 2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose, alpha-D-mannopyranose-(1-2)-alpha-D-mannopyranose-(1-2)-alpha-D-mannopyranose-(1-3)-alpha-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose, ... (4 entities in total) |
機能のキーワード | substrate complex, hydrolase |
由来する生物種 | Ostrinia furnacalis |
タンパク質・核酸の鎖数 | 2 |
化学式量合計 | 91124.08 |
構造登録者 | |
主引用文献 | Chen, W.,Qu, M.,Zhou, Y.,Yang, Q. Structural analysis of group II chitinase (ChtII) catalysis completes the puzzle of chitin hydrolysis in insects J. Biol. Chem., 293:2652-2660, 2018 Cited by PubMed Abstract: Chitin is a linear homopolymer of -acetyl-β-d-glucosamines and a major structural component of insect cuticles. Chitin hydrolysis involves glycoside hydrolase family 18 (GH18) chitinases. In insects, chitin hydrolysis is essential for periodic shedding of the old cuticle ecdysis and proceeds via a pathway different from that in the well studied bacterial chitinolytic system. Group II chitinase (ChtII) is a widespread chitinolytic enzyme in insects and contains the greatest number of catalytic domains and chitin-binding domains among chitinases. In Lepidopterans, ChtII and two other chitinases, ChtI and Chi-h, are essential for chitin hydrolysis. Although ChtI and Chi-h have been well studied, the role of ChtII remains elusive. Here, we investigated the structure and enzymology of ChtII, a ChtII derived from the insect pest We present the crystal structures of two catalytically active domains of ChtII, ChtII-C1 and ChtII-C2, both in unliganded form and complexed with chitooligosaccharide substrates. We found that ChtII-C1 and ChtII-C2 both possess long, deep substrate-binding clefts with endochitinase activities. ChtII exhibited structural characteristics within the substrate-binding cleft similar to those in Chi-h and ChtI. However, ChtII lacked structural elements favoring substrate binding beyond the active sites, including an extra wall structure present in Chi-h. Nevertheless, the numerous domains in ChtII may compensate for this difference; a truncation containing one catalytic domain and three chitin-binding modules (ChtII-B4C1) displayed activity toward insoluble polymeric substrates that was higher than those of Chi-h and ChtI. Our observations provide the last piece of the puzzle of chitin hydrolysis in insects. PubMed: 29317504DOI: 10.1074/jbc.RA117.000119 主引用文献が同じPDBエントリー |
実験手法 | X-RAY DIFFRACTION (2.45 Å) |
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