Abstract:

Protein lysine modifications play important roles in gene regulation, transcription, metabolism and other biological processes. Lysine 2-hydroxyisobutyrylation on histones has recently been discovered as a novel protein modification, and this modification was associated with germ cell differentiation. The problem whether the novel modification may or may not exist in prokaryotes was investigated. A number of 2-hydroxyisobutyrylated proteins and sites were identified in Proteus mirabilis using affinity enrichment, high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) and bioinformatics. The modified proteins were further characterized according to protein distribution properties, interaction networks and pathways. The results indicated that lysine 2-hydroxyisobutyrylation is widely distributed in prokaryotes, and may be significant in biological functions in prokaryotes.

Key words: Proteus mirabilis, 2-hydroxyisobutyrylation, high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS), lysine, post-translational modifications (PTMs)