AUTHOR=Liao Jiahn-Haur , Tsai Cheng-Han , Patel Sanjay G. , Yang Jhih-Tian , Tu I-Fan , Lo Cicero Matteo , Lipka-Lloyd Magdalena , Wu Wan-Ling , Shen Wen-Jie , Ho Meng-Ru , Chou Chi-Chi , Sharma Garima R. , Okanishi Hiroki , Luk Louis Y. P. , Tsai Yu-Hsuan , Wu Shih-Hsiung TITLE=Acetylome of Acinetobacter baumannii SK17 Reveals a Highly-Conserved Modification of Histone-Like Protein HU JOURNAL=Frontiers in Molecular Biosciences VOLUME=4 YEAR=2017 URL=https://www.frontiersin.org/journals/molecular-biosciences/articles/10.3389/fmolb.2017.00077 DOI=10.3389/fmolb.2017.00077 ISSN=2296-889X ABSTRACT=

Lysine acetylation is a prevalent post-translational modification in both eukaryotes and prokaryotes. Whereas this modification is known to play pivotal roles in eukaryotes, the function and extent of this modification in prokaryotic cells remain largely unexplored. Here we report the acetylome of a pair of antibiotic-sensitive and -resistant nosocomial pathogen Acinetobacter baumannii SK17-S and SK17-R. A total of 145 lysine acetylation sites on 125 proteins was identified, and there are 23 acetylated proteins found in both strains, including histone-like protein HU which was found to be acetylated at Lys13. HU is a dimeric DNA-binding protein critical for maintaining chromosomal architecture and other DNA-dependent functions. To analyze the effects of site-specific acetylation, homogenously Lys13-acetylated HU protein, HU(K13ac) was prepared by genetic code expansion. Whilst not exerting an obvious effect on the oligomeric state, Lys13 acetylation alters both the thermal stability and DNA binding kinetics of HU. Accordingly, this modification likely destabilizes the chromosome structure and regulates bacterial gene transcription. This work indicates that acetyllysine plays an important role in bacterial epigenetics.