Parks Anastacia R, Will Jessica L, Mathew Liju G, Massier Sébastien, Hardouin Julie, Escalante-Semerena Jorge C
Department of Microbiology, University of Georgia, Athens, GA 30602, USA.
University of Rouen Normandie, INSA Rouen Normandie, CNRS, Polymers, Biopolymers, Surfaces Laboratory UMR 6270, F-76000 Rouen, France.
Pathogens. 2025 Jun 20;14(7):616. doi: 10.3390/pathogens14070616.
Here we report that the Typhimurium NatB (NatB) protein -terminal acetyltransferase acetylated the -terminal methionine of the nucleoid-associated HU proteins. Our findings were supported by an in vitro analysis of acetylation of the HUα and HUβ proteins and lysine-null (K-null) variants, and by an in vivo analysis of the effect of acetylation on HU-mediated transcriptional regulation of a known target of HU, the promoter. NatB did not acetylate the initiating methionines of HU proteins that were oxidized to methionine sulfoxide, but the reduction of these methionine sulfoxide residues restored the acetylation of HU proteins by NatB. These results demonstrate that the HU proteins are bona fide substrates for the methionine sulfoxide reductases MsrA and MsrB. Finally, we showed that the acetyltransferase, YfmK, is a functional homolog of NatB, and that YfmK acetylates the amino group of the initiating methionine of the HU protein (HBsu).
在此我们报告，鼠伤寒沙门氏菌的NatB（N-末端乙酰转移酶）可将类核相关HU蛋白的N-末端甲硫氨酸乙酰化。对HUα和HUβ蛋白以及赖氨酸缺失（K-缺失）变体的乙酰化体外分析，以及对乙酰化作用于HU介导的已知HU靶标（即启动子）转录调控的体内分析，均支持了我们的研究结果。NatB不会乙酰化已氧化为甲硫氨酸亚砜的HU蛋白的起始甲硫氨酸，但这些甲硫氨酸亚砜残基的还原可恢复NatB对HU蛋白的乙酰化作用。这些结果表明，HU蛋白是甲硫氨酸亚砜还原酶MsrA和MsrB的真正底物。最后，我们表明乙酰转移酶YfmK是NatB的功能同源物，且YfmK可将HU蛋白（HBsu）起始甲硫氨酸的氨基乙酰化。
