Keyword search (3,448 papers available)


Global view of the Clostridium thermocellum cellulosome revealed by quantitative proteomic analysis.

Author(s): Gold ND, Martin VJ

J Bacteriol. 2007 Oct;189(19):6787-95 Authors: Gold ND, Martin VJ

Article GUID: 17644599
Proteomic analysis of Clostridium thermocellum ATCC 27405 reveals the upregulation of an alternative transhydrogenase-malate pathway and nitrogen assimilation in cells grown on cellulose.

Author(s): Burton E, Martin VJ

Can J Microbiol. 2012 Dec;58(12):1378-88 Authors: Burton E, Martin VJ

Article GUID: 23210995
Expression of a library of fungal β-glucosidases in Saccharomyces cerevisiae for the development of a biomass fermenting strain.

Author(s): Wilde C, Gold ND, Bawa N, Tambor JH, Mougharbel L, Storms R, Martin VJ

Appl Microbiol Biotechnol. 2012 Aug;95(3):647-59 Authors: Wilde C, Gold ND, Bawa N, Tambor JH, Mougharbel L, Storms R, Martin VJ

Article GUID: 22218767
Effects of synthetic cohesin-containing scaffold protein architecture on binding dockerin-enzyme fusions on the surface of Lactococcus lactis.

Author(s): Wieczorek AS, Martin VJ

Microb Cell Fact. 2012 Dec 15;11:160 Authors: Wieczorek AS, Martin VJ

Article GUID: 23241215
Reconstitution of a 10-gene pathway for synthesis of the plant alkaloid dihydrosanguinarine in Saccharomyces cerevisiae.

Author(s): Fossati E, Ekins A, Narcross L, Zhu Y, Falgueyret JP, Beaudoin GA, Facchini PJ, Martin VJ

Nat Commun. 2014;5:3283 Authors: Fossati E, Ekins A, Narcross L, Zhu Y, Falgueyret JP, Beaudoin GA, Facchini PJ, Martin VJ

Article GUID: 24513861
Deconstructing the genetic basis of spent sulphite liquor tolerance using deep sequencing of genome-shuffled yeast.

Author(s): Pinel D, Colatriano D, Jiang H, Lee H, Martin VJ

Biotechnol Biofuels. 2015;8:53 Authors: Pinel D, Colatriano D, Jiang H, Lee H, Martin VJ

Article GUID: 25866561
Synthesis of Morphinan Alkaloids in Saccharomyces cerevisiae.

Author(s): Fossati E, Narcross L, Ekins A, Falgueyret JP, Martin VJ

PLoS One. 2015;10(4):e0124459 Authors: Fossati E, Narcross L, Ekins A, Falgueyret JP, Martin VJ

Article GUID: 25905794
An enzyme-coupled biosensor enables (S)-reticuline production in yeast from glucose.

Author(s): DeLoache WC, Russ ZN, Narcross L, Gonzales AM, Martin VJ, Dueber JE

Nat Chem Biol. 2015 Jul;11(7):465-71 Authors: DeLoache WC, Russ ZN, Narcross L, Gonzales AM, Martin VJ, Dueber JE

Article GUID: 25984720
Metabolic engineering of a tyrosine-overproducing yeast platform using targeted metabolomics.

Author(s): Gold ND, Gowen CM, Lussier FX, Cautha SC, Mahadevan R, Martin VJ

Microb Cell Fact. 2015 May 28;14:73 Authors: Gold ND, Gowen CM, Lussier FX, Cautha SC, Mahadevan R, Martin VJ

Article GUID: 26016674
Directed evolution of a fungal β-glucosidase in Saccharomyces cerevisiae.

Author(s): Larue K, Melgar M, Martin VJ

Biotechnol Biofuels. 2016;9:52 Authors: Larue K, Melgar M, Martin VJ

Article GUID: 26949413
Engineering of a Nepetalactol-Producing Platform Strain of Saccharomyces cerevisiae for the Production of Plant Seco-Iridoids.

Author(s): Campbell A, Bauchart P, Gold ND, Zhu Y, De Luca V, Martin VJ

ACS Synth Biol. 2016 05 20;5(5):405-14 Authors: Campbell A, Bauchart P, Gold ND, Zhu Y, De Luca V, Martin VJ

Article GUID: 26981892
Seamless site-directed mutagenesis of the Saccharomyces cerevisiae genome using CRISPR-Cas9.

Author(s): Biot-Pelletier D, Martin VJ

J Biol Eng. 2016;10:6 Authors: Biot-Pelletier D, Martin VJ

Article GUID: 27134651
Reconstituting Plant Secondary Metabolism in Saccharomyces cerevisiae for Production of High-Value Benzylisoquinoline Alkaloids.

Author(s): Pyne ME, Narcross L, Fossati E, Bourgeois L, Burton E, Gold ND, Martin VJ

Methods Enzymol. 2016;575:195-224 Authors: Pyne ME, Narcross L, Fossati E, Bourgeois L, Burton E, Gold ND, Martin VJ

Article GUID: 27417930
Mining Enzyme Diversity of Transcriptome Libraries through DNA Synthesis for Benzylisoquinoline Alkaloid Pathway Optimization in Yeast.

Author(s): Narcross L, Bourgeois L, Fossati E, Burton E, Martin VJ

ACS Synth Biol. 2016 12 16;5(12):1505-1518 Authors: Narcross L, Bourgeois L, Fossati E, Burton E, Martin VJ

Article GUID: 27442619
Persistence of Escherichia coli in batch and continuous vermicomposting systems.

Author(s): Hénault-Ethier L, Martin VJ, Gélinas Y

Waste Manag. 2016 Oct;56:88-99 Authors: Hénault-Ethier L, Martin VJ, Gélinas Y

Article GUID: 27499290
Title:Directed evolution of a fungal β-glucosidase in Saccharomyces cerevisiae.
Authors:Larue K,  Melgar M,  Martin VJ
Link:https://www.ncbi.nlm.nih.gov/pubmed/26949413?dopt=Abstract
DOI:10.1186/s13068-016-0470-9
Category:Biotechnol Biofuels
PMID:26949413
Dept Affiliation: GENOMICS
1 Department of Biology, Centre for Structural and Functional Genomics, Concordia University, 7141 Sherbrooke West, Montreal, QC H4B 1R6 Canada.

Description:

Directed evolution of a fungal ß-glucosidase in Saccharomyces cerevisiae.

Biotechnol Biofuels. 2016;9:52

Authors: Larue K, Melgar M, Martin VJ

Abstract

BACKGROUND: ß-glucosidases (BGLs) catalyze the hydrolysis of soluble cellodextrins to glucose and are a critical component of cellulase systems. In order to engineer Saccharomyces cerevisiae for the production of ethanol from cellulosic biomass, a BGL tailored to industrial bioconversions is needed.

RESULTS: We applied a directed evolution strategy to a glycosyl hydrolase family 3 (GH3) BGL from Aspergillus niger (BGL1) by expressing a library of mutated bgl1 genes in S. cerevisiae and used a two-step functional screen to identify improved enzymes. Twelve BGL variants that supported growth of S. cerevisiae on cellobiose and showed increased activity on the synthetic substrate p-nitrophenyl-ß-D-glucopyranoside were identified and characterized. By performing kinetic experiments, we found that a Tyr ? Cys substitution at position 305 of BGL1 dramatically reduced transglycosidation activity that causes inhibition of the hydrolytic reaction at high substrate concentrations. Targeted mutagenesis demonstrated that the position 305 residue is critical in GH3 BGLs and likely determines the extent to which transglycosidation reactions occur. We also found that a substitution at Gln(140) reduced the inhibitory effect of glucose and could be combined with the Y305C substitution to produce a BGL with decreased sensitivity to both the product and substrate. Using the crystal structure of a GH3 BGL from A. aculeatus, we mapped a group of beneficial mutations to the ß/a domain of the molecule and postulate that this region modulates activity through subunit interactions. Six BGL variants were identified with substitutions in the MFa pre-sequence that was used to mediate secretion of the protein. Substitutions at Pro(21) or Val(22) of the MFa pre-sequence could produce up to a twofold increase in supernatant hydrolase activity and provides evidence that expression and/or secretion was an additional factor limiting hydrolytic activity.

CONCLUSIONS: Using directed evolution on BGL1, we identified a key residue that controls hydrolytic and transglycosidation reactions in GH3 BGLs. We also found that several beneficial mutations could be combined and increased the hydrolytic activity for both synthetic and natural substrates.

PMID: 26949413 [PubMed]