title: The Modes of Action of ChiIII, a Chitinase from Mushroom Coprinopsis cinerea, Shift with Changes in the Length of GlcNAc Oligomers.
abstract: A putative class III endochitinase (ChiIII) was reported previously to be expressed dominantly in fruiting bodies of Coprinopsis cinerea, and its expression levels increased with the maturation of the fruiting bodies. This paper further reports that ChiIII is a novel chitinase with exo- and endoactivities. When the substrate was (GlcNAc)3-5, ChiIII exhibited exoactivity, releasing GlcNAc processively from the reducing end of (GlcNAc)3-5; when the substrate was (GlcNAc)6-7, the activity of ChiIII shifted to an endoacting enzyme, randomly splitting chitin oligosaccharides to various shorter oligosaccharides. This shift in the mode of action of ChiIII may be related to its stronger hydrolytic capacity to degrade chitin in fungal cell walls. The predicted structure of ChiIII shows that it lacks the α+β domain insertion; however, its substrate binding cleft seems to be deeper than that of common endochitinases but shallower and more open than that of common exochitinases, which may be related to its exo- and endohydrolytic activities.
authors: Jiangsu Key Laboratory for Microbes and Microbial Functional Genomics, Jiangsu Engineering and Technology Research Center for Industrialization of Microbial Resources, College of Life Science, Nanjing Normal University , Nanjing 210023, People's Republic of China.
authors: Xin
authors: X
authors: Niu
authors: Jiangsu Key Laboratory for Microbes and Microbial Functional Genomics, Jiangsu Engineering and Technology Research Center for Industrialization of Microbial Resources, College of Life Science, Nanjing Normal University , Nanjing 210023, People's Republic of China.
authors: Cui-Cui
authors: CC
authors: Liu
authors: Jiangsu Key Laboratory for Microbes and Microbial Functional Genomics, Jiangsu Engineering and Technology Research Center for Industrialization of Microbial Resources, College of Life Science, Nanjing Normal University , Nanjing 210023, People's Republic of China.
authors: Yuan-Jing
authors: YJ
authors: Xiong
authors: Jiangsu Key Laboratory for Microbes and Microbial Functional Genomics, Jiangsu Engineering and Technology Research Center for Industrialization of Microbial Resources, College of Life Science, Nanjing Normal University , Nanjing 210023, People's Republic of China.
authors: Ming-Mei
authors: MM
authors: Yang
authors: Jiangsu Key Laboratory for Microbes and Microbial Functional Genomics, Jiangsu Engineering and Technology Research Center for Industrialization of Microbial Resources, College of Life Science, Nanjing Normal University , Nanjing 210023, People's Republic of China.
authors: Fei
authors: F
authors: Ma
authors: Jiangsu Key Laboratory for Microbes and Microbial Functional Genomics, Jiangsu Engineering and Technology Research Center for Industrialization of Microbial Resources, College of Life Science, Nanjing Normal University , Nanjing 210023, People's Republic of China.
authors: Zhong-Hua
authors: ZH
authors: Liu
authors: Jiangsu Key Laboratory for Microbes and Microbial Functional Genomics, Jiangsu Engineering and Technology Research Center for Industrialization of Microbial Resources, College of Life Science, Nanjing Normal University , Nanjing 210023, People's Republic of China.
authors: Sheng
authors: S
authors: Yuan
mesh_terms: D000117:Acetylglucosamine / Q000378:metabolism*; D000363:Agaricales / Q000737:chemistry / Q000201:enzymology* / Q000235:genetics; D000595:Amino Acid Sequence; D002686:Chitin / Q000737:chemistry / Q000378:metabolism; D002688:Chitinases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D005656:Fungal Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D009844:Oligosaccharides / Q000737:chemistry* / Q000378:metabolism*; D013379:Substrate Specificity
chemical_list: D005656:Fungal Proteins; D009844:Oligosaccharides; D002686:Chitin; D002688:Chitinases; D000117:Acetylglucosamine
keywords: Coprinopsis cinerea; chitin; chitin oligosaccharide; chitinase; fungal cell walls