Structural and functional studies on novel bacterial lysine-deacetylases and their roles in bacterial physiology and during bacterial infection.

赖氨酸乙酰化是一种与细胞代谢密切相关的翻译后修饰。赖氨酸乙酰化修饰系统的功能障碍导致从癌症到神经退行性疾病和代谢性疾病的严重疾病的发展。赖氨酸乙酰转移酶催化乙酰辅酶A上的乙酰基转移到赖氨酸侧链上，脱乙酰酶将乙酰基转移到赖氨酸侧链上，脱乙酰酶可分为NAD+依赖的Sirtuins和Zn 2+依赖的经典脱乙酰酶（KDAC）。到目前为止，对原核生物脱乙酰酶的研究大多集中在单一的去乙酰化酶上。我们应用生物信息学方法，在原核生物中鉴定了数千种新的经典KDAC。几种KDAC在致病性革兰氏阳性和革兰氏阴性细菌中编码，例如嗜肺军团菌、霍乱弧菌、肺炎克雷伯菌和金黄色葡萄球菌。对于来自K的一个KDAC。pneumoniae，一种严重的人类病原体，我们可以解决apo形式和与抑制剂的复合物中的晶体结构。在这项研究中，将结合联合收割机合成生物学方法，结构生物学与微生物学方法和质谱法，以了解如何选择新的原核KDAC影响细菌的生理学和病理生理学。翻译后赖氨酸乙酰化是一种感知细胞环境中的代谢变化并通过改变蛋白质功能来翻译这些变化以调节细胞过程的方式。由于细菌，特别是致病菌，必须对其环境的变化做出快速反应并适应这些条件，赖氨酸乙酰化可能在这些过程中发挥重要作用。该项目中获得的结果不仅有助于了解赖氨酸乙酰化在正常细菌生理学中的作用，而且对于探索解决赖氨酸乙酰化机制以治疗严重细菌感染的新型治疗策略的潜力也将是有价值的。考虑到多重耐药菌株在环境中的传播，这一主题目前非常重要，当这些菌株在医院传播时，这可能导致严重的问题。

Lysine-acetylation is a post-translational modification that is tightly connected to the cellular metabolism. Dysfunction in the lysine-acetylation modifcation system results in the development of severe diseases ranging from cancer to neurodegenerative diseases and metabolic diseases. Lysine-acetyltransferases catalyze the transfer of the acetyl-moiety from acetyl-CoA to the lysine side chain, and deacetylases remove it. Deacetylases can be classified into NAD+-dependent Sirtuins and Zn2+-dependent classical deacetylases (KDACs). So far, most research on deacetylases in prokaryotes focussed on a single sirtuin deacetylase. We applied a bioinformatics approach and identified thousands of novel classical KDACs in prokaryotes. Several KDACs are encoded in pathogenic Gram-positive and Gram-negative bacteria, such as Legionella pneumophilae, Vibrio cholerae, Klebsiella pneumoniae and Staphylococcus aureus. For one KDAC from K. pneumoniae, a severe human pathogen, we could solve crystal structures in the apo-form and in the complexes with inhibitors. In this research proposal will combine synthetic biological approaches, structural biology with microbiological approaches and mass-spectrometry to understand how selected novel prokaryotic KDACs affects bacterial physiology and pathophysiology. Post-translational lysine-acetylation is a way to sense metabolic changes in the cellular environment and to translate these changes to regulate cellular processes by altering protein function. As bacteria, and particularly pathogenic bacteria, have to respond fast to alterations in their environment and to adopt to these conditions, lysine acetylation might play an important role in these processes. The results obtained in this project will not only help to understand the role of lysine acetylation in normal bacterial physiology, it will also be valuable to explore the potential of a novel therapeutic strategy tackling the lysine acetylation machinery to treat severe bacterial infections. This topic is currently highly important considering the spread of multi-resistant bacterial strains in the environment, which can lead severe problems when those strains spread in hospitals.