Phosphodiesterase activity of CvfA is required for virulence in Staphylococcus aureus
Phosphodiesterase activity of CvfA is required for virulence in Staphylococcus aureus
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DOI：
10.1074/jbc.m705309200
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发表时间：
2008-01-25
影响因子：
4.8
通讯作者：
Sekimizu, Kazuhisa
中科院分区：
文献类型：
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作者：
Nagata, Makiko;Kaito, Chikara;Sekimizu, Kazuhisa
我们之前使用家蚕感染模型将 cvfA 基因 (SA1129) 鉴定为金黄色葡萄球菌中的一种新型毒力调节因子。 cvfA 基因在各种病原菌中保守，有助于 agr 位点的表达，agr 位点是一种全局毒力调节因子，控制编码各种外蛋白（例如溶血素）的基因的表达。 CvfA 蛋白具有跨膜结构域、RNA 结合结构域（KH 结构域）和金属依赖性磷酸水解酶结构域（HD 结构域）。我们在这里报告了通过测量其磷酸二酯酶活性从大肠杆菌膜组分中纯化重组 CvfA 蛋白。在 Mn2+ 存在下，纯化的 CvfA 蛋白可水解 RNA 3' 末端的 2', 3'-环 AMP、2', 3'-环 GMP 和 2', 3'-环磷酸的磷酸二酯键。 HD 结构域中氨基酸取代的 CvfA 突变蛋白显着降低了磷酸二酯酶活性。此外，编码具有低磷酸二酯酶活性的蛋白质的突变cvfA基因不能补充cvfA缺失突变体中溶血素产生的减少或对蚕的杀伤能力的减弱。这些结果表明，CvfA 蛋白的磷酸二酯酶活性是金黄色葡萄球菌的毒力所必需的。
We previously identified the cvfA gene (SA1129) as a novel virulence regulator in Staphylococcus aureus using the silkworm infection model. The cvfA gene, which is conserved among various pathogenic bacteria, contributes to the expression of the agr locus, a global virulence regulator that controls the expression of genes encoding various exoproteins, such as hemolysin. CvfA protein has a transmembrane domain, an RNA binding domain (KH domain), and a metal-dependent phosphohydrolase domain (HD domain). We report here the purification of recombinant CvfA protein from a membrane fraction of Escherichia coli by measuring its phosphodiesterase activity. Purified CvfA protein hydrolyzed the phosphodiester linkage of 2 ', 3 '-cyclic AMP, 2 ', 3 '-cyclic GMP, and 2 ', 3 '-cyclic phosphate at the 3 '-terminal of RNA in the presence of Mn2+. CvfA mutant proteins with amino acid substitutions in the HD domain had significantly decreased phosphodiesterase activity. Furthermore, mutated cvfA genes encoding proteins with low phosphodiesterase activity did not complement the decreased hemolysin production or the attenuated killing ability against silkworms in the cvfA deletion mutant. These results suggest that the phosphodiesterase activity of CvfA protein is required for virulence in S. aureus.