Journal Article
mBio, vol. 9, iss. 5, 2018
Authors
David G. Christensen, Jesse G. Meyer, Jackson T. Baumgartner, Alexandria K. D’Souza, William C. Nelson, Samuel H. Payne, Misty L. Kuhn, Birgit Schilling, Alan J. Wolfe, Nancy E. Freitag
Abstract
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ε-Lysine acetylation is one of the most abundant and important posttranslational modifications across all domains of life. One of the best-studied effects of acetylation occurs in eukaryotes, where acetylation of histone tails activates gene transcription. Although bacteria do not have true histones,
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ε-lysine acetylation is prevalent; however, the role of these modifications is mostly unknown. We constructed an
E. coli
strain that lacked both known acetylation mechanisms to identify four new
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ε-lysine acetyltransferases (RimI, YiaC, YjaB, and PhnO). We used mass spectrometry to determine the substrate specificity of these acetyltransferases. Structural analysis of selected substrate proteins revealed site-specific preferences for enzymatic acetylation that had little overlap with the preferences of the previously reported acetyl-phosphate nonenzymatic acetylation mechanism. Finally, YiaC and YfiQ appear to regulate flagellum-based motility, a phenotype critical for pathogenesis of many organisms. These acetyltransferases are highly conserved and reveal deeper and more complex roles for bacterial posttranslational modification.
