Signäs C, Raucci G, Jönsson K, Lindgren P E, Anantharamaiah G M, Höök M, Lindberg M
Department of Microbiology, Swedish University of Agricultural Sciences, Uppsala.
Proc Natl Acad Sci U S A. 1989 Jan;86(2):699-703. doi: 10.1073/pnas.86.2.699.
Binding of cells of Staphylococcus aureus to fibronectin, which may represent a mechanism of host tissue adherence, involves a fibronectin-receptor protein present on the bacterial surface. Cloning of a gene coding for a staphylococcal fibronectin-binding protein and construction of a fusion protein with fibronectin-binding properties was previously reported from our laboratory. We have now sequenced the gene and deduced a primary sequence of the fibronectin-binding protein. The protein resembles other cell-wall-associated proteins on Gram-positive bacteria in that it (i) appears to be anchored in the cell membrane via its C-terminal end, (ii) contains a proline-rich repeating unit outside the membrane anchor, and (iii) contains a long (36-amino acid) signal sequence at the N terminus. The fibronectin-binding activity has been localized to a domain composed of a 38-amino acid unit repeated completely three times and partially a fourth time; the identity between the three 38-amino acid sequences varies from 42 to 87%. Three synthetic peptides mimicking the structure of each 38-amino acid unit were constructed. All three peptides interacted with fibronectin, as indicated by their ability to inhibit binding of fibronectin to staphylococcal cells, whereas an unrelated 37-amino acid peptide showed no inhibitory activity.
金黄色葡萄球菌细胞与纤连蛋白的结合可能是宿主组织黏附的一种机制，这涉及到细菌表面存在的一种纤连蛋白受体蛋白。我们实验室之前报道过编码葡萄球菌纤连蛋白结合蛋白的基因克隆以及具有纤连蛋白结合特性的融合蛋白的构建。我们现在已对该基因进行了测序，并推导了纤连蛋白结合蛋白的一级序列。该蛋白与革兰氏阳性菌上其他细胞壁相关蛋白相似，即：（i）似乎通过其C末端锚定在细胞膜中；（ii）在膜锚定之外含有富含脯氨酸的重复单元；（iii）在N末端含有一个长的（36个氨基酸）信号序列。纤连蛋白结合活性已定位到一个由一个38个氨基酸的单元完全重复三次且部分重复第四次组成的结构域；这三个38个氨基酸序列之间的同一性在42%至87%之间。构建了模拟每个38个氨基酸单元结构的三种合成肽。如它们抑制纤连蛋白与葡萄球菌细胞结合的能力所示，所有这三种肽都与纤连蛋白相互作用，而一种不相关的37个氨基酸的肽则没有抑制活性。
