Profile of protein lysine propionylation in Aeromonas hydrophila and its role in enzymatic regulation.

Protein lysine propionylation (Kpr) modification is a novel post-translational modification (PTM) of prokaryotic cells that was recently discovered; however, it is not clear how this modification regulates bacterial life. In this study, the protein Kpr modification profile in Aeromonas hydrophila was identified by high specificity antibody-based affinity enrichment combined with high resolution LC MS/MS. A total of 98 lysine-propionylated peptides with 59 Kpr proteins were identified, most of which were associated with energy metabolism, transcription and translation processes. To further understand the role of Kpr modified proteins, the K168 site on malate dehydrogenase (MDH) and K608 site on acetyl-coenzyme A synthetase (AcsA) were subjected to site-directed mutation to arginine (R) and glutamine (Q) to simulate deacylation and propionylation, respectively. Subsequent measurement of the enzymatic activity showed that the K168 site of Kpr modification on MDH may negatively regulate the MDH enzymatic activity while also affecting the survival of mdh derivatives when using glucose as the carbon source, whereas Kpr modification of K608 of AcsA does not. Overall, the results of this study indicate that protein Kpr modification plays an important role in bacterial biological functions, especially those involved in the activity of metabolic enzymes. • Lysine propionylation profile was analyzed in A. hydrophila. • Lysine propionylation involved in multiple metabolic pathways. • Kpr on MDH K168 site negatively regulates enzymatic activity. [ABSTRACT FROM AUTHOR]