Molecular insights into substrate specificity and thermal stability of a bacterial GH5-CBM27 endo-1,4-β-D-mannanase
| Autor: | Junio Cota, Andreia N. Meza, Camila R. Santos, Mário T. Murakami, Joice Helena Paiva, Rolf A. Prade, Fabio M. Squina, Roberto Ruller, Thabata M. Alvarez |
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| Rok vydání: | 2011 |
| Předmět: |
Models
Molecular Protein Denaturation Stereochemistry Surface Properties Mannan endo-1 4-β-mannosidase Amino Acid Motifs Molecular Sequence Data Crystallography X-Ray Substrate Specificity Gram-Negative Anaerobic Straight Curved and Helical Rods Glycoside hydrolase family 5 Bacterial Proteins Structural Biology Thermotoga petrophila RKU-1 Catalytic Domain Enzyme Stability Mannosidases Molecule Thermal stability Amino Acid Sequence Maltose Thermotoga petrophila Sequence Deletion chemistry.chemical_classification Substrate recognition Chemistry Crystal structure Ligand (biochemistry) Glucose binding Barrel Kinetics Enzyme Glucose Carbohydrate binding module 27 Protein Binding |
| Zdroj: | Journal of structural biology. 177(2) |
| ISSN: | 1095-8657 |
| Popis: | The breakdown of β-1,4-mannoside linkages in a variety of mannan-containing polysaccharides is of great importance in industrial processes such as kraft pulp delignification, food processing and production of second-generation biofuels, which puts a premium on studies regarding the prospection and engineering of β-mannanases. In this work, a two-domain β-mannanase from Thermotoga petrophila that encompasses a GH5 catalytic domain with a C-terminal CBM27 accessory domain, was functionally and structurally characterized. Kinetic and thermal denaturation experiments showed that the CBM27 domain provided thermo-protection to the catalytic domain, while no contribution on enzymatic activity was observed. The structure of the catalytic domain determined by SIRAS revealed a canonical (α/β) 8 -barrel scaffold surrounded by loops and short helices that form the catalytic interface. Several structurally related ligand molecules interacting with TpMan were solved at high-resolution and resulted in a wide-range representation of the subsites forming the active-site cleft with residues W134, E198, R200, E235, H283 and W284 directly involved in glucose binding. |
| Databáze: | OpenAIRE |
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