Lindmark H, Jacobsson K, Frykberg L, Guss B
Department of Microbiology, Swedish University of Agricultural Sciences, Uppsala, Sweden.
Infect Immun. 1996 Oct;64(10):3993-9. doi: 10.1128/iai.64.10.3993-3999.1996.
By screening a genomic lambda library of Streptococcus equi subsp. zooepidemicus, we have cloned and sequenced a gene, termed fnz, encoding a fibronectin (Fn)-binding protein called FNZ. On the basis of the deduced amino acid sequence of FNZ, the mature protein has a molecular mass of approximately 61 kDa. Analysis of FNZ reveals a structural organization similar to that of other cell surface proteins from streptococci and staphylococci. The Fn-binding activity is localized to two domains in the C-terminal part of FNZ. One domain is composed of five repeats, which contain a motif similar to what has earlier been found in other Fn-binding proteins in streptococci and staphylococci. The first and second repeats are separated by a short stretch of amino acids, including the motif LAGESGET, which is an important part of the second Fn-binding domain. This motif is also present in an Fn-binding domain (UR) in protein F of Streptococcus pyogenes. A fusion protein covering the Fn-binding domain of FNZ inhibits the binding of the 29-kDa N-terminal fragment of Fn to cells of various streptococcal species as well as to Staphylococcus aureus.
通过筛选马链球菌兽疫亚种的基因组λ文库，我们克隆并测序了一个名为fnz的基因，该基因编码一种名为FNZ的纤连蛋白（Fn）结合蛋白。根据FNZ推导的氨基酸序列，成熟蛋白的分子量约为61 kDa。对FNZ的分析揭示了一种与链球菌和葡萄球菌的其他细胞表面蛋白相似的结构组织。Fn结合活性定位于FNZ C末端部分的两个结构域。一个结构域由五个重复序列组成，这些重复序列包含一个与先前在链球菌和葡萄球菌的其他Fn结合蛋白中发现的基序相似的基序。第一个和第二个重复序列被一小段氨基酸隔开，包括基序LAGESGET，它是第二个Fn结合结构域的重要组成部分。该基序也存在于化脓性链球菌蛋白F的Fn结合结构域（UR）中。覆盖FNZ的Fn结合结构域的融合蛋白可抑制Fn的29 kDa N末端片段与各种链球菌以及金黄色葡萄球菌细胞的结合。
