Systematic Analysis of Lysine Succinylation in Streptococcus mutans

Lysine succinylation (Ksuc) is a novel post-translational modification (PTM), which regulates biological functions in bacteria. Streptococcus mutans has been identified as a predominant cariogenic pathogen responsible for the initiation and progression of dental caries. However, lysine succinylation in S. mutans has not yet been investigated. In this study, a global lysine succinylome was analyzed to examine Ksuc in S. mutans. Overall, 2250 succinylated sites in 580 proteins were identified. Quantitative analysis demonstrated that Ksuc substrates were substantially altered in the biofilm growth state compared with the planktonic growth state. These differentially succinylated proteins were distributed across various cellular components and involved in crucial biological pathways, including translation, ribosomal structure, and biogenesis. Furthermore, lysine acetylation and succinylation extensively overlapped in S. mutans, and these bimodified proteins were associated with biofilm formation, glycolysis, and pyruvate metabolism. These results provided a foundation to further investigate the role of Ksuc in S. mutans pathogenicity and expand our understanding of Ksuc functions in bacterial physiology and virulence.