Systematic Analysis of Lysine Acetylation in the Halophilic Archaeon Haloferax mediterranei

Lysine acetylation is a reversible and highly regulated post-translational modification that plays a critical role in regulating many aspects of cellular processes, both in bacteria and in eukaryotes. However, this modification has not been systematically studied in archaea. Herein, we report the lysine acetylome of a model haloarchaeon, Haloferax mediterranei. Using immunoaffinity enrichment and LC–MS/MS analysis, we identified 1017 acetylation sites in 643 proteins, accounting for 17.3% of the total proteins in this haloarchaeon. Bioinformatics analysis indicated that lysine acetylation mainly distributes in cytoplasm (94%) and participates in protein biosynthesis and carbon metabolism. Specifically, the acetylation of key enzymes in PHBV biosynthesis further suggested that acetylation plays a key role in the energy and carbon storage. In addition, a survey of the acetylome revealed a universal rule in acetylated motifs: a positively charged residue (K, R, or H) located downstream of acetylated lysine a...