Recombinases are responsible for homologous recombination (HR), proper genome maintenance, and accurate deoxyribonucleic acid (DNA) duplication. Moreover, HR plays a determining role in DNA transaction processes such as DNA replication, repair, recombination, and transcription. Staphylococcus aureus, an opportunistic pathogen, usually causes respiratory infections such as sinusitis, skin infections, and food poisoning. To date, the role of the RecA gene product in S. aureus remains obscure. In this study, we attempted to map the functional properties of the RecA protein. S. aureus expresses the recA gene product in vivo upon exposure to the DNA-damaging agents, ultraviolet radiation, and methyl methanesulfonate. The recombinant purified S. aureus RecA protein displayed strong single-stranded DNA affinity compared to feeble binding to double-stranded DNA. Interestingly, the RecA protein is capable of invasion and formed displacement loops and readily performed strand-exchange activities with an oligonucleotide-based substrate. Notably, the S. aureus RecA protein hydrolyzed the DNA-dependent adenosine triphosphate and cleaved LexA, showing the conserved function of coprotease. This study provides the functional characterization of the S. aureus RecA protein and sheds light on the canonical processes of homologous recombination, which are conserved in the gram-positive foodborne pathogen S. aureus.

重组酶负责同源重组 (HR)、适当的基因组维护和准确的脱氧核糖核酸 (DNA) 复制。此外，人力资源在 DNA 交易过程中起着决定性的作用，例如 DNA 复制、修复、重组和转录。金黄色葡萄球菌是一种机会性病原体，通常会引起呼吸道感染，如鼻窦炎、皮肤感染和食物中毒。迄今为止，RecA 基因产物在金黄色葡萄球菌中的作用仍然不清楚。在这项研究中，我们试图绘制 RecA 蛋白的功能特性。金黄色葡萄球菌在体内表达recA基因产物暴露于 DNA 损伤剂、紫外线辐射和甲磺酸甲酯。与双链 DNA 的微弱结合相比，重组纯化的金黄色葡萄球菌RecA 蛋白表现出较强的单链 DNA 亲和力。有趣的是，RecA 蛋白能够侵入并形成置换环，并且很容易与基于寡核苷酸的底物进行链交换活动。值得注意的是，金黄色葡萄球菌RecA 蛋白水解依赖于 DNA 的三磷酸腺苷并切割 LexA，显示出蛋白酶的保守功能。本研究提供了金黄色葡萄球菌的功能特征RecA 蛋白揭示了同源重组的典型过程，这些过程在革兰氏阳性食源性病原体金黄色葡萄球菌中是保守的。