5w11

Biochemical and structural insights into the catalytic mechanism of thermostable cellobiohydrolase Cel7A from industrially relevant fungus Myceliophthora thermophila

spinqualitylabelsall models 5w11, resolution 2.31Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 5w11 is a 2 chain structure with sequence from Myceliophthora thermophila. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: 144, CTR, MAN, NAG NonStd Res: PCA Activity: Cellulose 1,4-beta-cellobiosidase (reducing end), with EC number 3.2.1.176 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Publication Abstract from PubMed Cellobiohydrolases hydrolyze cellulose, a linear polymer with glucose monomers linked exclusively by beta-1,4 glycosidic linkages. The widespread hydrogen bonding network tethers individual cellulose polymers forming crystalline cellulose, which prevent the access of hydrolytic enzymes and water molecules. The most abundant enzyme secreted by Myceliophthora thermophila M77 in response to the presence of biomass is the cellobiohydrolase MtCel7A, which is composed by a GH7-catalytic domain (CD), a linker and a CBM1-type carbohydrate binding module. GH7 cellobiohydrolases have been studied before and structural models have been proposed. However, current available GH7 crystal structures only define separate catalytic domains and/or cellulose-binding modules and do not include the full length structures that are involved in shaping the catalytic mode of operation. In this study, we determined the 3D-structure of catalytic domain using X-ray crystallography and retrieved the full length enzyme envelope via small-angle X-ray scattering (SAXS) technique. The SAXS data reveal a tadpole-like molecular shape with a rigid linker connecting the CD and CBM. Our biochemical studies show that MtCel7A has higher catalytic efficiency and thermostability as well as lower processivity when compared to the well-studied TrCel7A from Trichoderma reesei. Based on a comparison of the crystallographic structures of CDs and their molecular dynamic simulations, we demonstrate that MtCel7A has considerably higher flexibility than TrCel7A. In particular, loops that cover the active site are more flexible and undergo higher conformational fluctuations, which might account for decreased processivity and enhanced enzymatic efficiency. Our statistical coupling analysis (SCA) suggests co-evolution of amino acid clusters comprising the catalytic site of MtCel7A, which correlate with the steps in the catalytic cycle of the enzyme. This article is protected by copyright. All rights reserved. Biochemical and structural insights into a thermostable cellobiohydrolase from Myceliophthora thermophila.,Kadowaki MAS, Higasi P, de Godoy MO, Prade RA, Polikarpov I FEBS J. 2017 Dec 8. doi: 10.1111/febs.14356. PMID:29222836 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Cellobiohydrolase 3D structures

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