Lysine Phoshoglycerylation Is Widespread in Bacteria and Overlaps with Acylation

Area of Science:

• Biochemistry
• Proteomics
• Microbiology

Background:

• Phosphoglycerylation is a non-enzymatic protein modification involving a phosphoglyceryl group attached to lysine.
• This modification is found in glycolytic enzymes and may regulate glycolytic flux.

Purpose of the Study:

• To conduct the first proteomic analysis of phosphoglycerylation in bacteria, specifically in Streptococcus pyogenes.
• To investigate the prevalence and conservation of phosphoglycerylation across different bacterial species.

Main Methods:

• Proteomic profiling of phosphoglyceryl-lysine in S. pyogenes under varying culture conditions.
• Mass spectrometry (MS/MS) was used for identification, including a novel diagnostic cyclic immonium ion.
• Re-analysis of existing phosphoproteomes from 14 bacterial species.

Main Results:

• Identified 370 lysine phosphoglycerylation sites in 123 S. pyogenes proteins.
• Higher phosphoglycerylation occurred in defined medium with fructose compared to rich medium with glucose.
• Phosphoglycerylation is widespread in bacteria, with conserved sites across species.
• Significant overlap observed between phosphoglycerylation and other lysine acylations (acetylation, succinylation).

Conclusions:

• Phosphoglycerylation is a common post-translational modification in bacteria, conserved across many species.
• This modification, along with other acylations, may play a role in joint metabolic regulation.
• Further research is needed to understand the functional significance of low-stoichiometry phosphoglycerylation.