CelG from Clostridium cellulolyticum: a multidomain endoglucanase acting efficiently on crystalline cellulose
| Autor: | Chantal Tardif, Christian Gaudin, Sandrine Pagès, Anne Belaich, Laurent Gal, Jean-Pierre Belaich |
|---|---|
| Přispěvatelé: | Institut de biologie structurale et microbiologie (IBSM), Université de la Méditerranée - Aix-Marseille 2-Université Paul Cézanne - Aix-Marseille 3-Université de Provence - Aix-Marseille 1-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Dijon, Institut Agro |
| Rok vydání: | 1997 |
| Předmět: |
Cellulase
Biology Protein Engineering Clostridium cellulolyticum Microbiology Substrate Specificity 03 medical and health sciences chemistry.chemical_compound Clostridium Bacterial Proteins [SDV.BBM] Life Sciences [q-bio]/Biochemistry Molecular Biology Escherichia coli medicine [SDV.BBM]Life Sciences [q-bio]/Biochemistry Molecular Biology Binding site Cellulose Molecular Biology 030304 developmental biology 0303 health sciences Binding Sites 030306 microbiology Protein engineering Cellulose binding biology.organism_classification Recombinant Proteins Carboxymethyl cellulose Biochemistry chemistry biology.protein Research Article medicine.drug |
| Zdroj: | Journal of Bacteriology Journal of Bacteriology, American Society for Microbiology, 1997, 179 (21), pp.6595-6601. ⟨10.1128/jb.179.21.6595-6601.1997⟩ Journal of Bacteriology, 1997, 179 (21), pp.6595-6601. ⟨10.1128/jb.179.21.6595-6601.1997⟩ |
| ISSN: | 1098-5530 0021-9193 |
| Popis: | International audience; The gene coding for CelG, a family 9 cellulase from Clostridium cellulolyticum, was cloned and overexpressed in Escherichia coli. Four different forms of the protein were genetically engineered, purified, and studied: CelGL (the entire form of CelG), CelGcat1 (the catalytic domain of CelG alone), CelGcat2 (CelGcat1 plus 91 amino acids at the beginning of the cellulose binding domain [CBD]), and GST-CBD(CelG) (the CBD of CelG fused to glutathione S-transferase). The biochemical properties of CelG were compared with those of CelA, an endoglucanase from C. cellulolyticum which was previously studied. CelG, like CelA, was found to have an endo cutting mode of activity on carboxymethyl cellulose (CMC) but exhibited greater activity on crystalline substrates (bacterial microcrystalline cellulose and Avicel) than CelA. As observed with CelA, the presence of the nonhydrolytic miniscaffolding protein (miniCipC1) enhanced the activity of CelG on phosphoric acid swollen cellulose (PASC), but to a lesser extent. The absence of the CBD led to the complete inactivation of the enzyme. The abilities of CelG and GST-CBD(CelG) to bind various substrates were also studied. Although the entire enzyme is able to bind to crystalline cellulose at a limited number of sites, the chimeric protein GST-CBD(CelG) does not bind to either of the tested substrates (Avicel and PASC). The lack of independence between the two domains and the weak binding to cellulose suggest that this CBD-like domain may play a special role and be either directly or indirectly involved in the catalytic reaction. |
| Databáze: | OpenAIRE |
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