Institut für Hygiene und Mikrobiologie, Abteilung für Medizinische Mikrobiologie, Ruhr-Universität Bochum, Bochum, Germany.
FEMS Microbiol Lett. 2009 Nov;301(1):28-34. doi: 10.1111/j.1574-6968.2009.01798.x. Epub 2009 Sep 17.
Staphylococcus saprophyticus, an important cause of urinary tract infections in young women, expresses the surface protein SdrI, a member of the serine-aspartate repeat (SD) protein family. Here we analyse the fibronectin-binding ability of SdrI, as S. saprophyticus is known to bind fibronectin and there is no known SD protein with this function. This protein does not contain the binding motif typical for fibronectin-binding proteins. Using recombinant fragments of SdrI, we localized the binding domain in the A region and show that SdrI bound to the N-terminal 30-kDa fragment of fibronectin. The fibronectin-binding function was shown in the natural host using an SdrI knockout mutant that showed decreased binding to fibronectin compared with wild-type strain 7108.
腐生葡萄球菌是引起年轻女性尿路感染的重要原因，它表达表面蛋白 SdrI，该蛋白属于丝氨酸-天冬氨酸重复（SD）蛋白家族。在这里，我们分析了 SdrI 的纤连蛋白结合能力，因为已知腐生葡萄球菌可以结合纤连蛋白，而没有已知的具有这种功能的 SD 蛋白。该蛋白不包含典型的纤连蛋白结合蛋白的结合基序。使用 SdrI 的重组片段，我们将结合域定位在 A 区域，并表明 SdrI 与纤连蛋白的 N 端 30kDa 片段结合。在天然宿主中，使用 SdrI 敲除突变体显示出与野生型菌株 7108 相比结合纤连蛋白减少的功能来证明其具有纤连蛋白结合功能。
