Graduate School of Life Science, Hokkaido University, Sapporo 060-0810, Japan.
Protein Sci. 2011 Feb;20(2):406-16. doi: 10.1002/pro.573.
Staphylococci use cell wall-anchored proteins as adhesins to attach to host tissues. Staphylococcus saprophyticus, a uropathogenic species, has a unique cell wall-anchored protein, uro-adherence factor A (UafA), which shows erythrocyte binding activity. To investigate the mechanism of adhesion by UafA, we determined the crystal structure of the functional region of UafA at 1.5 Å resolution. The structure was composed of three domains, designated as the N2, N3, and B domains, arranged in a triangular relative configuration. Hemagglutination inhibition assay with domain-truncated mutants indicated that both N and B domains were necessary for erythrocyte binding. Based on these results, a novel manner of ligand binding in which the B domain acts as a functional domain was proposed as the adhesion mechanism of S. saprophyticus.
葡萄球菌利用细胞壁锚定蛋白作为黏附素附着到宿主组织上。腐生葡萄球菌是一种尿路致病性物种，具有独特的细胞壁锚定蛋白尿黏附因子 A（UafA），具有红细胞结合活性。为了研究 UafA 的黏附机制，我们以 1.5 Å 的分辨率确定了 UafA 的功能区域的晶体结构。该结构由三个结构域组成，分别命名为 N2、N3 和 B 结构域，以三角形的相对构型排列。用结构域截断突变体进行的血凝抑制试验表明，N 结构域和 B 结构域都是红细胞结合所必需的。基于这些结果，提出了一种新的配体结合方式，其中 B 结构域作为功能结构域，作为腐生葡萄球菌黏附的机制。
