↓ Skip to main content

Directed evolution of a fungal β-glucosidase in Saccharomyces cerevisiae

Overview of attention for article published in Biotechnology for Biofuels, March 2016
Altmetric Badge

About this Attention Score

  • In the top 25% of all research outputs scored by Altmetric
  • High Attention Score compared to outputs of the same age (80th percentile)
  • Good Attention Score compared to outputs of the same age and source (77th percentile)

Mentioned by

blogs
1 blog
twitter
2 tweeters

Citations

dimensions_citation
30 Dimensions

Readers on

mendeley
80 Mendeley
You are seeing a free-to-access but limited selection of the activity Altmetric has collected about this research output. Click here to find out more.
Title
Directed evolution of a fungal β-glucosidase in Saccharomyces cerevisiae
Published in
Biotechnology for Biofuels, March 2016
DOI 10.1186/s13068-016-0470-9
Pubmed ID
Authors

Kane Larue, Mindy Melgar, Vincent J. J. Martin

Abstract

β-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. 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-β-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 β/α domain of the molecule and postulate that this region modulates activity through subunit interactions. Six BGL variants were identified with substitutions in the MFα pre-sequence that was used to mediate secretion of the protein. Substitutions at Pro(21) or Val(22) of the MFα 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. 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.

Twitter Demographics

The data shown below were collected from the profiles of 2 tweeters who shared this research output. Click here to find out more about how the information was compiled.

Mendeley readers

The data shown below were compiled from readership statistics for 80 Mendeley readers of this research output. Click here to see the associated Mendeley record.

Geographical breakdown

Country Count As %
China 1 1%
Canada 1 1%
South Africa 1 1%
Unknown 77 96%

Demographic breakdown

Readers by professional status Count As %
Student > Ph. D. Student 18 23%
Researcher 17 21%
Student > Master 11 14%
Student > Postgraduate 9 11%
Student > Doctoral Student 6 8%
Other 9 11%
Unknown 10 13%
Readers by discipline Count As %
Agricultural and Biological Sciences 32 40%
Biochemistry, Genetics and Molecular Biology 20 25%
Environmental Science 3 4%
Immunology and Microbiology 3 4%
Chemistry 2 3%
Other 7 9%
Unknown 13 16%

Attention Score in Context

This research output has an Altmetric Attention Score of 8. This is our high-level measure of the quality and quantity of online attention that it has received. This Attention Score, as well as the ranking and number of research outputs shown below, was calculated when the research output was last mentioned on 05 September 2016.
All research outputs
#2,441,660
of 15,171,295 outputs
Outputs from Biotechnology for Biofuels
#183
of 1,148 outputs
Outputs of similar age
#52,255
of 268,571 outputs
Outputs of similar age from Biotechnology for Biofuels
#2
of 9 outputs
Altmetric has tracked 15,171,295 research outputs across all sources so far. Compared to these this one has done well and is in the 83rd percentile: it's in the top 25% of all research outputs ever tracked by Altmetric.
So far Altmetric has tracked 1,148 research outputs from this source. They receive a mean Attention Score of 4.4. This one has done well, scoring higher than 84% of its peers.
Older research outputs will score higher simply because they've had more time to accumulate mentions. To account for age we can compare this Altmetric Attention Score to the 268,571 tracked outputs that were published within six weeks on either side of this one in any source. This one has done well, scoring higher than 80% of its contemporaries.
We're also able to compare this research output to 9 others from the same source and published within six weeks on either side of this one. This one has scored higher than 7 of them.