Zhu Kemeng, Chen Huan, Jin Jin, Wang Ning, Ma Guixing, Huang Jiandong, Feng Youjun, Xin Jiuqing, Zhang Hongmin, Liu Henggui
State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, The Chinese Academy of Agricultural Sciences, Harbin, China.
Department of Biology, Guangdong Provincial Key Laboratory of Cell Microenvironment and Disease Research, Shenzhen Key Laboratory of Cell Microenvironment and SUSTech-HKU Joint Laboratories for Matrix Biology and Diseases, Southern University of Science and Technology, Shenzhen, China.
Front Cell Infect Microbiol. 2020 Apr 21;10:156. doi: 10.3389/fcimb.2020.00156. eCollection 2020.
() is the causative agent of pandemic pneumonia among pigs, namely, swine enzootic pneumonia. Although was first identified in 1965, little is known regarding its metabolic pathways, which might play a pivotal role during disease pathogenesis. Lipoate is an essential cofactor for enzymes important for central metabolism. However, the lipoate metabolism pathway in is definitely unclear. Here, we identified a novel gene, lpl, encoding a lipoate protein ligase in the genome of (Mhp-Lpl). This gene contains 1,032 base pairs and encodes a protein of 343 amino acids, which is between 7.5 and 36.09% identical to lipoate protein ligases (Lpls) of other species. Similar to its homologs in other species, Mhp-Lpl catalyzes the ATP-dependent activation of lipoate to lipoyl-AMP and the transfer of the activated lipoyl onto the lipoyl domains of GcvH (Mhp H) . Enzymatic and mutagenesis analysis indicate that residue K56 within the SKT sequence of Mhp H protein is the lipoyl moiety acceptor site. The three-dimensional structure showed typical lipoate protein ligase folding, with a large N-terminal domain and a small C-terminal domain. The large N-terminal domain is responsible for the full enzymatic activity of Mhp-Lpl. The identification and characterization of Mhp-Lpl will be beneficial to our understanding of metabolism.
Lipoic acid is an essential cofactor for the activation of some enzyme complexes involved in key metabolic processes. Lipoate protein ligases (Lpls) are responsible for the metabolism of lipoic acid. To date, little is known regarding the Lpls in . In this study, we identified a lipoate protein ligase of . We further analyzed the function, overall structure and ligand-binding site of this protein. The lipoate acceptor site on GcvH was also identified. Together, these findings reveal that Lpl exists in and will provide a basis for further exploration of the pathway of lipoic acid metabolism in .
（）是猪大流行性肺炎的病原体，即猪地方流行性肺炎。尽管它于1965年首次被鉴定出来，但关于其代谢途径的了解甚少，而代谢途径可能在疾病发病机制中起关键作用。硫辛酸是对中心代谢重要的酶的必需辅因子。然而，（该病原体中）硫辛酸代谢途径尚不清楚。在此，我们在（该病原体）基因组中鉴定出一个新基因lpl，其编码硫辛酸蛋白连接酶（Mhp-Lpl）。该基因包含1032个碱基对，编码一个343个氨基酸的蛋白质，该蛋白质与其他物种的硫辛酸蛋白连接酶（Lpls）的同一性在7.5%至36.09%之间。与其他物种中的同源物相似，Mhp-Lpl催化硫辛酸依赖ATP激活为脂酰-AMP，并将活化的脂酰转移到（该病原体的）GcvH（Mhp H）的脂酰结构域上。酶促和诱变分析表明，Mhp H蛋白SKT序列中的K56残基是脂酰部分受体位点。三维结构显示出典型的硫辛酸蛋白连接酶折叠，具有一个大的N端结构域和一个小的C端结构域。大的N端结构域负责Mhp-Lpl的全部酶活性。Mhp-Lpl的鉴定和表征将有助于我们对（该病原体）代谢的理解。
硫辛酸是激活参与关键代谢过程的一些酶复合物的必需辅因子。硫辛酸蛋白连接酶（Lpls）负责硫辛酸的代谢。迄今为止，关于（该病原体中的）Lpls了解甚少。在本研究中，我们鉴定了（该病原体的）一种硫辛酸蛋白连接酶。我们进一步分析了该蛋白质的功能、整体结构和配体结合位点。还鉴定了（该病原体的）GcvH上的硫辛酸受体位点。总之，这些发现表明Lpl存在于（该病原体中），并将为进一步探索（该病原体中）硫辛酸代谢途径提供基础。
