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Updated: Jul 10, 2025
11:08
A Facile Protocol to Generate Site-Specifically Acetylated Proteins in Escherichia Coli
Published on: December 9, 2017
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Characterizing lysine acetylation of glucokinase
Nour Fatema1, Xinyu Li1, Qinglei Gan2
1Cell and Molecular Biology Program, University of Arkansas, Fayetteville, Arkansas, USA.
Protein Science : a Publication of the Protein Society
|November 24, 2023
Summary
Acetylation of Escherichia coli glucokinase (GK) reduces its activity by impairing substrate binding, particularly at sites K214 and K216. This study reveals acetylation mechanisms and challenges glutamine substitution as a mimic for acetylated lysine.
Area of Science:
- Biochemistry
- Enzymology
- Molecular Biology
Background:
- Glucokinase (GK) is crucial for glycolysis, catalyzing glucose phosphorylation.
- Proteomic studies identified multiple acetylation sites on Escherichia coli GK.
- The functional impact of GK acetylation remains largely unknown.
Purpose of the Study:
- To investigate the functional consequences of lysine acetylation on Escherichia coli GK activity.
- To elucidate the mechanisms of GK acetylation and deacetylation.
- To compare different methods for mimicking lysine acetylation in GK.
Main Methods:
- Genetic code expansion to produce site-specifically acetylated GK variants.
- Enzyme assays and kinetic analyses.
- In vitro acetylation and deacetylation assays.
- Comparison of glutamine substitution with genetic acetyllysine incorporation.
Main Results:
- Lysine acetylation significantly decreases GK activity.
- Acetylation of K214 and K216 at the active site entrance impairs substrate binding.
- Glutamine substitution is not always an effective mimic for acetylated lysine.
- Escherichia coli GK can be acetylated by acetyl-phosphate and deacetylated by CobB.
Conclusions:
- Site-specific acetylation negatively regulates Escherichia coli GK activity.
- Acetylation at K214 and K216 is critical for the observed decrease in GK function.
- The study provides insights into GK acetylation/deacetylation mechanisms and highlights limitations of mimicry strategies.
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