Michel DION
Professeur Université
janvier 2004 - juin 2018
| Équipe : |
Thèmes de recherche
Glyco-enzymologie, microbiologie, biotechnologies
Publications
1 publication
Ogonda, Lydia A; Saumonneau, Amélie; Dion, Michel; Muge, Edward K; Wamalwa, Benson M; Mulaa, Francis J; Tellier, Charles
Characterization and engineering of two new GH9 and GH48 cellulases from a Bacillus pumilus isolated from Lake Bogoria Article de journal
Dans: Biotechnology Letters, vol. 43, p. 691–700, 2021.
@article{ogondacharacterization,
title = {Characterization and engineering of two new GH9 and GH48 cellulases from a Bacillus pumilus isolated from Lake Bogoria},
author = {Lydia A Ogonda and Amélie Saumonneau and Michel Dion and Edward K Muge and Benson M Wamalwa and Francis J Mulaa and Charles Tellier},
doi = {10.1007/s10529-020-03056-z},
year = {2021},
date = {2021-01-01},
journal = {Biotechnology Letters},
volume = {43},
pages = {691–700},
publisher = {Springer},
abstract = {Objectives. To search for new alkaliphilic cellulases and to improve their efficiency on crystalline cellulose through molecular engineering
Results. Two novel cellulases, BpGH9 and BpGH48, from a Bacillus pumilus strain were identified, cloned and biochemically characterized. BpGH9 is a modular endocellulase belonging to the glycoside hydrolase 9 family (GH9), which contains a catalytic module (GH) and a carbohydrate-binding module belonging to class 3 and subclass c (CBM3c). This enzyme is extremely tolerant to high alkali pH and remains significantly active at pH 10. BpGH48 is an exocellulase, belonging to the glycoside hydrolase 48 family (GH48) and acts on the reducing end of oligo-β1,4 glucanes. A truncated form of BpGH9 and a chimeric fusion with an additional CBM3a module was constructed. The deletion of the CBM3c module results in a significant decline in the catalytic activity. However, fusion of CBM3a, although in a non native position, enhanced the activity of BpGH9 on crystalline cellulose.
Conclusions. A new alkaliphilic endocellulase BpGH9, was cloned and engineered as a fusion protein (CBM3a-BpGH9), which led to an improved activity on crystalline cellulose.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Objectives. To search for new alkaliphilic cellulases and to improve their efficiency on crystalline cellulose through molecular engineering
Results. Two novel cellulases, BpGH9 and BpGH48, from a Bacillus pumilus strain were identified, cloned and biochemically characterized. BpGH9 is a modular endocellulase belonging to the glycoside hydrolase 9 family (GH9), which contains a catalytic module (GH) and a carbohydrate-binding module belonging to class 3 and subclass c (CBM3c). This enzyme is extremely tolerant to high alkali pH and remains significantly active at pH 10. BpGH48 is an exocellulase, belonging to the glycoside hydrolase 48 family (GH48) and acts on the reducing end of oligo-β1,4 glucanes. A truncated form of BpGH9 and a chimeric fusion with an additional CBM3a module was constructed. The deletion of the CBM3c module results in a significant decline in the catalytic activity. However, fusion of CBM3a, although in a non native position, enhanced the activity of BpGH9 on crystalline cellulose.
Conclusions. A new alkaliphilic endocellulase BpGH9, was cloned and engineered as a fusion protein (CBM3a-BpGH9), which led to an improved activity on crystalline cellulose.
Results. Two novel cellulases, BpGH9 and BpGH48, from a Bacillus pumilus strain were identified, cloned and biochemically characterized. BpGH9 is a modular endocellulase belonging to the glycoside hydrolase 9 family (GH9), which contains a catalytic module (GH) and a carbohydrate-binding module belonging to class 3 and subclass c (CBM3c). This enzyme is extremely tolerant to high alkali pH and remains significantly active at pH 10. BpGH48 is an exocellulase, belonging to the glycoside hydrolase 48 family (GH48) and acts on the reducing end of oligo-β1,4 glucanes. A truncated form of BpGH9 and a chimeric fusion with an additional CBM3a module was constructed. The deletion of the CBM3c module results in a significant decline in the catalytic activity. However, fusion of CBM3a, although in a non native position, enhanced the activity of BpGH9 on crystalline cellulose.
Conclusions. A new alkaliphilic endocellulase BpGH9, was cloned and engineered as a fusion protein (CBM3a-BpGH9), which led to an improved activity on crystalline cellulose.
2 publications
Arab-Jaziri, Faten; Bissaro, Bastien; Tellier, Charles; Dion, Michel; Fauré, Régis; O'Donohue, Michael J
Enhancing the chemoenzymatic synthesis of arabinosylated xylo-oligosaccharides by GH51 α-l-arabinofuranosidase Article de journal
Dans: Carbohydrate Research, vol. 401, p. 64–72, 2015, ISSN: 1873426X.
@article{Arab-Jaziri2015,
title = {Enhancing the chemoenzymatic synthesis of arabinosylated xylo-oligosaccharides by GH51 α-l-arabinofuranosidase},
author = {Faten Arab-Jaziri and Bastien Bissaro and Charles Tellier and Michel Dion and Régis Fauré and Michael J O'Donohue},
doi = {10.1016/j.carres.2014.10.029},
issn = {1873426X},
year = {2015},
date = {2015-01-01},
journal = {Carbohydrate Research},
volume = {401},
pages = {64--72},
publisher = {Elsevier Ltd},
abstract = {Random mutagenesis was performed on the α-l-arabinofuranosidase of Thermobacillus xylanilyticus in order to enhance its ability to perform transarabinofuranosylation using natural xylo-oligosaccharides as acceptors. To achieve this goal, a two-step, high-throughput digital imaging protocol involving a colorimetric substrate was used to screen a library of 30,000 mutants. In the first step this screen selected for hydrolytically-impaired mutants, and in the second step the screen identified mutants whose global activity was improved in the presence of a xylo-oligosaccharide mixture. Thereby, 199 mutants displaying lowered hydrolytic activity and modified properties were detected. In the presence of these xylo-oligosaccharides, most of the 199 (i.e., 70%) enzymes were less inhibited and some (18) mutants displayed an unambiguous alleviation of inhibition (textless25% loss of activity). More precise monitoring of reactions catalyzed by the most promising mutants revealed a significant improvement of the synthesis yields of transglycosylation products (up to 18% compared to 9% for the parental enzyme) when xylobiose was present in the reaction. Genetic analysis of improved mutants revealed that many of the amino acid substitutions that correlate with the modified phenotype are located in the vicinity of the active site, particularly in subsite -1. Consequently, we hypothesize that these mutations modify the active site topology or the molecular interaction network of the l-arabinofuranoside donor substrate, thus impairing the hydrolysis and concomitantly favoring transglycosylation onto natural acceptors.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Random mutagenesis was performed on the α-l-arabinofuranosidase of Thermobacillus xylanilyticus in order to enhance its ability to perform transarabinofuranosylation using natural xylo-oligosaccharides as acceptors. To achieve this goal, a two-step, high-throughput digital imaging protocol involving a colorimetric substrate was used to screen a library of 30,000 mutants. In the first step this screen selected for hydrolytically-impaired mutants, and in the second step the screen identified mutants whose global activity was improved in the presence of a xylo-oligosaccharide mixture. Thereby, 199 mutants displaying lowered hydrolytic activity and modified properties were detected. In the presence of these xylo-oligosaccharides, most of the 199 (i.e., 70%) enzymes were less inhibited and some (18) mutants displayed an unambiguous alleviation of inhibition (textless25% loss of activity). More precise monitoring of reactions catalyzed by the most promising mutants revealed a significant improvement of the synthesis yields of transglycosylation products (up to 18% compared to 9% for the parental enzyme) when xylobiose was present in the reaction. Genetic analysis of improved mutants revealed that many of the amino acid substitutions that correlate with the modified phenotype are located in the vicinity of the active site, particularly in subsite -1. Consequently, we hypothesize that these mutations modify the active site topology or the molecular interaction network of the l-arabinofuranoside donor substrate, thus impairing the hydrolysis and concomitantly favoring transglycosylation onto natural acceptors.
André-Miral, Corinne; Koné, Fankroma Mt; Solleux, Claude; Grandjean, Cyrille; Dion, Michel; Tran, Vinh; Tellier, Charles
De novo design of a trans-β-N-acetylglucosaminidase activity from a GH1 β-glycosidase by mechanism engineering Article de journal
Dans: Glycobiology, vol. 25, no. 4, p. 394–402, 2015, ISSN: 14602423.
@article{Andre-Miral2015,
title = {De novo design of a trans-β-N-acetylglucosaminidase activity from a GH1 β-glycosidase by mechanism engineering},
author = {Corinne André-Miral and Fankroma Mt Koné and Claude Solleux and Cyrille Grandjean and Michel Dion and Vinh Tran and Charles Tellier},
doi = {10.1093/glycob/cwu121},
issn = {14602423},
year = {2015},
date = {2015-01-01},
journal = {Glycobiology},
volume = {25},
number = {4},
pages = {394--402},
abstract = {Glycoside hydrolases are particularly abundant in all areas of metabolism as they are involved in the degradation of natural polysaccharides and glycoconjugates. These enzymes are classified into 133 families (CAZy server, http://www.cazy.org) in which members of each family have a similar structure and catalytic mechanism. In order to understand better the structure/function relationships of these enzymes and their evolution and to develop new robust evolved glycosidases, we undertook to convert a Family 1 thermostable β-glycosidase into an exo-β-N-acetylglucosaminidase. This latter activity is totally absent in Family 1, while natural β-hexosaminidases belong to CAZy Families 3, 20 and 84. Using molecular modeling, we first showed that the docking of N-acetyl-d-glucosamine in the subsite -1 of the β-glycosidase from Thermus thermophilus (TtβGly) suggested several steric conflicts with active site amino-acids (N163, E338) induced by the N-acetyl group. Both N163A and N163D-E338G mutations induced significant N-acetylglucosaminidase activity in TtβGly. The double mutant N163D-E338G was also active on the bicyclic oxazoline substrate, suggesting that this mutated enzyme uses a catalytic mechanism involving a substrate-assisted catalysis with a noncovalent oxazoline intermediate, similar to the N-acetylglucosaminidases from Families 20 and 84. Furthermore, a very efficient trans-N-acetylglucosaminidase activity was observed when the double mutant was incubated in the presence of NAG-oxazoline as a donor and N-methyl-O-benzyl-N-(β-d-glucopyranosyl)-hydroxylamine as an acceptor. More generally, this work demonstrates that it is possible to exchange the specificities and catalytic mechanisms with minimal changes between phylogenetically distant protein structures.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Glycoside hydrolases are particularly abundant in all areas of metabolism as they are involved in the degradation of natural polysaccharides and glycoconjugates. These enzymes are classified into 133 families (CAZy server, http://www.cazy.org) in which members of each family have a similar structure and catalytic mechanism. In order to understand better the structure/function relationships of these enzymes and their evolution and to develop new robust evolved glycosidases, we undertook to convert a Family 1 thermostable β-glycosidase into an exo-β-N-acetylglucosaminidase. This latter activity is totally absent in Family 1, while natural β-hexosaminidases belong to CAZy Families 3, 20 and 84. Using molecular modeling, we first showed that the docking of N-acetyl-d-glucosamine in the subsite -1 of the β-glycosidase from Thermus thermophilus (TtβGly) suggested several steric conflicts with active site amino-acids (N163, E338) induced by the N-acetyl group. Both N163A and N163D-E338G mutations induced significant N-acetylglucosaminidase activity in TtβGly. The double mutant N163D-E338G was also active on the bicyclic oxazoline substrate, suggesting that this mutated enzyme uses a catalytic mechanism involving a substrate-assisted catalysis with a noncovalent oxazoline intermediate, similar to the N-acetylglucosaminidases from Families 20 and 84. Furthermore, a very efficient trans-N-acetylglucosaminidase activity was observed when the double mutant was incubated in the presence of NAG-oxazoline as a donor and N-methyl-O-benzyl-N-(β-d-glucopyranosyl)-hydroxylamine as an acceptor. More generally, this work demonstrates that it is possible to exchange the specificities and catalytic mechanisms with minimal changes between phylogenetically distant protein structures.
2014
Teze, David; Hendrickx, Johann; Czjzek, Mirjam; Ropartz, David; Sanejouand, Yves-Henri; Tran, Vinh; Tellier, Charles; Dion, Michel
Semi-rational approach for converting a GH1 ß-glycosidase into a ß-transglycosidase Article de journal
Dans: Protein Engineering, Design & Selection, vol. 27, no. 1, p. 13–19, 2014.
@article{teze2014semi,
title = {Semi-rational approach for converting a GH1 ß-glycosidase into a ß-transglycosidase},
author = {David Teze and Johann Hendrickx and Mirjam Czjzek and David Ropartz and Yves-Henri Sanejouand and Vinh Tran and Charles Tellier and Michel Dion},
doi = {10.1093/protein/gzt057},
year = {2014},
date = {2014-01-01},
urldate = {2014-01-01},
journal = {Protein Engineering, Design & Selection},
volume = {27},
number = {1},
pages = {13--19},
publisher = {Oxford University Press},
abstract = {A large number of retaining glycosidases catalyze both hydrolysis and transglycosylation reactions, but little is known about what determines the balance between these two activities (transglycosylation/hydrolysis ratio). We previously obtained by directed evolution the mutants F401S and N282T of Thermus thermophilus β-glycosidase (Ttβ-gly, glycoside hydrolase family 1 (GH1)), which display a higher transglycosylation/hydrolysis ratio than the wild-type enzyme. In order to find the cause of these activity modifications, and thereby set up a generic method for easily obtaining transglycosidases from glycosidases, we determined their X-ray structure. No major structural changes could be observed which could help to rationalize the mutagenesis of glycosidases into transglycosidases. However, as these mutations are highly conserved in GH1 β-glycosidases and are located around the −1 site, we pursued the isolation of new transglycosidases by targeting highly conserved amino acids located around the active site. Thus, by single-point mutagenesis on Ttβ-gly, we created four new mutants that exhibit improved synthetic activity, producing disaccharides in yields of 68–90% against only 36% when native Ttβ-gly was used. As all of the chosen positions were well conserved among GH1 enzymes, this approach is most probably a general route to convert GH1 glycosidases into transglycosidases.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
A large number of retaining glycosidases catalyze both hydrolysis and transglycosylation reactions, but little is known about what determines the balance between these two activities (transglycosylation/hydrolysis ratio). We previously obtained by directed evolution the mutants F401S and N282T of Thermus thermophilus β-glycosidase (Ttβ-gly, glycoside hydrolase family 1 (GH1)), which display a higher transglycosylation/hydrolysis ratio than the wild-type enzyme. In order to find the cause of these activity modifications, and thereby set up a generic method for easily obtaining transglycosidases from glycosidases, we determined their X-ray structure. No major structural changes could be observed which could help to rationalize the mutagenesis of glycosidases into transglycosidases. However, as these mutations are highly conserved in GH1 β-glycosidases and are located around the −1 site, we pursued the isolation of new transglycosidases by targeting highly conserved amino acids located around the active site. Thus, by single-point mutagenesis on Ttβ-gly, we created four new mutants that exhibit improved synthetic activity, producing disaccharides in yields of 68–90% against only 36% when native Ttβ-gly was used. As all of the chosen positions were well conserved among GH1 enzymes, this approach is most probably a general route to convert GH1 glycosidases into transglycosidases.