title: Carbohydrate-binding modules influence substrate specificity of an endoglucanase from Clostridium thermocellum.
abstract: Most cellulases contain carbohydrate-binding modules (CBMs) that largely contribute to their activity for insoluble substrates. Clostridium thermocellum Cel5E is an endoglucanase having xylanolytic activity. The Cel5E originally has a family 11 CBM preferentially binding to β-1,4- and β-1,3-1,4-mixed linkage glucans. In this study, we replaced the CBM with a different type of CBM, either a family 3 microcrystalline cellulose-directed CBM from Clostridium josui scaffoldin, or a family 6 xylan-directed CBM from Clostridium stercorarium xylanase 11A. Chimeric endoglucanases showed enhanced activity that was affected by CBM binding specificity. These chimeric enzymes could efficiently degrade milled lignocellulosic materials, such as corn hulls, because of heterologous components in the plant cell wall, indicating that diverse CBMs play roles in degradation of lignocellulosic materials.
authors.affiliation: a Graduate School of Regional Innovation Studies , Mie University , Tsu , Japan.
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Ichikawa
authors.affiliation: a Graduate School of Regional Innovation Studies , Mie University , Tsu , Japan.
authors.forename: Mitsuki
authors.initials: M
authors.lastname: Yoshida
authors.affiliation: a Graduate School of Regional Innovation Studies , Mie University , Tsu , Japan.|b Graduate School of Bioresources , Mie University , Tsu , Japan.
authors.forename: Shuichi
authors.initials: S
authors.lastname: Karita
authors.affiliation: b Graduate School of Bioresources , Mie University , Tsu , Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Kondo
authors.affiliation: b Graduate School of Bioresources , Mie University , Tsu , Japan.
authors.forename: Masakazu
authors.initials: M
authors.lastname: Goto
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D002352:Carrier Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D002480:Cellulase / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D048013:Acetivibrio thermocellus / Q000201:enzymology* / Q000235:genetics; D043364:Endo-1,4-beta Xylanases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D057075:Enzyme Assays; D015870:Gene Expression; D005936:Glucans / Q000378:metabolism; D006868:Hydrolysis; D007700:Kinetics; D008031:Lignin / Q000378:metabolism; D060847:Metabolic Engineering; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D011993:Recombinant Fusion Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D013379:Substrate Specificity
chemical_list: D001426:Bacterial Proteins; D002352:Carrier Proteins; D005936:Glucans; D011993:Recombinant Fusion Proteins; C036909:lignocellulose; C074074:cellulose binding protein A, Clostridium cellulovorans; D008031:Lignin; D002480:Cellulase; D043364:Endo-1,4-beta Xylanases
keywords: carbohydrate-binding module; cellulose; xylanase