Two multimodular endoglucanases in glycoside hydrolase family 5, Cel5 and Cel5, share 73% identity and exhibit similar modular structures: family 1 carbohydrate-binding module (CBM1); catalytic domain; CBMX2; module of unknown function. However, they differed in their biochemical properties and catalytic performance. Cel5 showed optimal activity at pH 4.0 and 70 °C, maintaining stability at 70 °C (>80% activity). Conversely, Cel5 is optimal at pH 3.0 and 50 °C (>50% activity at 50 °C). Cel5 excels in degrading CMC-Na (256 U/mg vs 53 U/mg of Cel5). Five domain-truncated (TM1-TM5) and four domain-replaced (RM1-RM4) mutants of Cel5 with the counterparts of Cel5 were constructed, and their enzymatic properties were compared with those of the wild type. Only RM1, with Cel5-CBM1, displayed enhanced thermostability and activity. The hydrolysis of pretreated corn stover was reduced in most TM and RM mutants. Molecular dynamics simulations revealed interdomain interactions within the multimodular endoglucanase, potentially affecting its structural stability and complex biological catalytic processes.
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http://dx.doi.org/10.1021/acs.biomac.4c00660 | DOI Listing |
Biomacromolecules
September 2024
College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing 100083, China.
Int J Biol Macromol
July 2024
Carbohydrate Enzyme Biotechnology Laboratory, Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, Assam, India. Electronic address:
Cellulases from GH9 family show endo-, exo- or processive endocellulase activity, but the reason behind the variation is unclear. A GH9 recombinant endoglucanase, AtGH9C-CBM3A-CBM3B from Acetivibrio thermocellus was structurally characterized for conformation, binding and dynamics assessment. Modeled AtGH9C-CBM3A-CBM3B depicted (α/α)-barrel structure with Asp98, Asp101 and Glu489 acting as catalytic triad.
View Article and Find Full Text PDFBiochim Biophys Acta Proteins Proteom
January 2024
Centro de Ciências Naturais e Humanas, Universidade Federal do ABC (UFABC), Santo André, SP, Brazil. Electronic address:
Cellulases from anaerobic fungi are enzymes less-studied biochemically and structurally than cellulases from bacteria and aerobic fungi. Currently, only thirteen GH5 cellulases from anaerobic fungi were biochemically characterized and two crystal structures were reported. In this context, here, we report the functional and biophysical characterization of a novel multi-modular cellulosomal GH5 endoglucanase from the anaerobic gut fungus Piromyces finnis (named here PfGH5).
View Article and Find Full Text PDFInt J Biol Macromol
July 2023
Carbohydrate Enzyme Biotechnology Laboratory, Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, Assam, India. Electronic address:
A recombinant β-1,4 endoglucanase, AtGH9C-CBM3A-CBM3B from Acetivibrio thermocellus ATCC27405 was explored for biochemical properties and the role of its associated CBMs in catalysis. The gene expressing full-length multi-modular β-1,4-endoglucanase (AtGH9C-CBM3A-CBM3B) and its truncated derivatives (AtGH9C-CBM3A, AtGH9C, CBM3A and CBM3B) were independently cloned and expressed in Escherichia coli BL21(DE3) cells and purified. AtGH9C-CBM3A-CBM3B showed maximal activity at 55 °C and pH 7.
View Article and Find Full Text PDFJ Biol Chem
June 2023
Department of Chemistry and Manchester Institute of Biotechnology, The University of Manchester, Manchester, UK. Electronic address:
The β-glucans are structurally varied, naturally occurring components of the cell walls, and storage materials of a variety of plant and microbial species. In the human diet, mixed-linkage glucans [MLG - β-(1,3/4)-glucans] influence the gut microbiome and the host immune system. Although consumed daily, the molecular mechanism by which human gut Gram-positive bacteria utilize MLG largely remains unknown.
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