The gram‐negative anaerobe Porphyromonas gingivalis is not only a keystone periodontal pathogen but also an emerging systemic pathogen. Although the newly discovered protein post‐translational modification (PTM), lysine succinylation (Ksuc), appears to play an important role in modulating metabolic processes in bacteria, this PTM has not been investigated in P gingivalis. In this study, we used a highly sensitive proteomics approach combining affinity enrichment with high‐resolution liquid chromatography coupled with tandem mass spectrometry to examine Ksuc in P gingivalis. In total, 345 Ksuc sites in 233 proteins were identified and determined to be involved in a variety of cellular processes. In the region surrounding Ksuc sites, lysine residues were drastically overrepresented and sequence motifs with succinyl‐lysine flanked by a lysine at the +3 or +6 positions appear to be unique to this pathogen. Additionally, our results suggest a crosstalk between Ksuc and glycosylation, but the overlap between Ksuc and acetylation in P gingivalis is quite different from that observed in other organisms. Notably, Ksuc was observed in proteins associated with established virulence factors, including gingipains, fimbriae, RagB, and PorR. Moreover, products of the factors necessary for P gingivalis in vitro survival (18.5%) were found to be succinylated at lysine sites and the same was observed in products of fitness factors for P gingivalis survival in both abscess and epithelial cell colonization environments (12%). Collectively, these results suggest that Ksuc may be a new mechanism in modulating the virulence, adaptation, and fitness of P gingivalis.

中文翻译：

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牙周病原体牙龈卟啉单胞菌中赖氨酸琥珀酰化酶的整体分析。

革兰氏阴性厌氧菌牙龈卟啉单胞菌不仅是基石牙周病原体，而且还是一种新兴的全身性病原体。尽管新发现的蛋白质翻译后修饰（PTM）（赖氨酸琥珀酰化（Ksuc））在调节细菌的代谢过程中起着重要作用，但尚未在牙龈卟啉单胞菌中对此PTM进行过研究。在这项研究中，我们使用了一种高灵敏度的蛋白质组学方法，将亲和力富集与高分辨率液相色谱结合串联质谱联用来检测牙龈卟啉单胞菌中的Ksuc。总共鉴定出233种蛋白质中的345个Ksuc位点，并确定它们参与了多种细胞过程。在Ksuc位点周围的区域中，赖氨酸残基显着过量表达，在+3或+6位置旁接有赖氨酸的琥珀酰赖氨酸序列基序似乎是该病原体所特有的。此外，我们的结果表明，Ksuc和糖基化之间存在串扰，但是在牙龈卟啉单胞菌中，Ksuc和乙酰化之间的重叠与在其他生物中观察到的完全不同。值得注意的是，在与已确定的毒力因子相关的蛋白质中观察到了Ksuc，其中包括姜黄素，菌毛，RagB和PorR。此外，牙龈卟啉单胞菌必需因子的乘积体外存活率（18.5％）在赖氨酸位点被琥珀酰化，在脓肿和上皮细胞定植环境中（12％）在牙龈卟啉单胞菌存活率的适应因子产品中也观察到了同样的结果。总体而言，这些结果表明，Ksuc可能是调节齿龈假单胞菌的毒力，适应性和适应性的新机制。