Hell W, Meyer H G, Gatermann S G
Institut für Hygiene und Mikrobiologie, Abteilung für Medizinische Mikrobiologie, Ruhr-Universität Bochum, Germany.
Mol Microbiol. 1998 Aug;29(3):871-81. doi: 10.1046/j.1365-2958.1998.00983.x.
A gene encoding a novel cell wall-associated protein of Staphylococcus saprophyticus that binds fibronectin and to sheep erythrocytes has been cloned and sequenced. The 4392 bp open reading frame codes for an amino acid sequence that is quite similar to the Atl, an autolysin, of Staphylococcus aureus and to the AtlE of S. epidermidis. The two regions of most pronounced homology code for an N-acetyl-muramyl-L-alanine amidase and for an endo-beta-N-acetyl-D-glucosaminidase. The cloned protein lysed cells of S. saprophyticus and Micrococcus luteus exogenously. Subcloning localized the enzymatic activities to the regions of high homology and demonstrated that the interposed sequence is responsible for the adhesive activities. Two allelic replacement mutants were constructed that lacked autolytic activity and adhesive properties. The N-terminal portion of the protein contains seven highly conserved, contiguous repeats with no similarity to published sequences. It lacks the motifs typical of Gram-positive surface proteins and shows a different overall organization. This autolysin/adhesin of S. saprophyticus (Aas) appears to represent a new class of staphylococcal adhesins.
编码腐生葡萄球菌一种与细胞壁相关的新型蛋白的基因已被克隆和测序，该蛋白可结合纤连蛋白并与绵羊红细胞结合。4392bp的开放阅读框编码的氨基酸序列与金黄色葡萄球菌的自溶素Atl以及表皮葡萄球菌的AtlE非常相似。同源性最明显的两个区域分别编码N-乙酰胞壁酰-L-丙氨酸酰胺酶和内切-β-N-乙酰-D-葡糖胺糖苷酶。克隆的蛋白可在体外裂解腐生葡萄球菌和藤黄微球菌的细胞。亚克隆将酶活性定位到高同源性区域，并证明插入序列负责黏附活性。构建了两个缺乏自溶活性和黏附特性的等位基因替换突变体。该蛋白的N端部分包含七个高度保守的连续重复序列，与已发表序列无相似性。它缺乏革兰氏阳性表面蛋白的典型基序，且整体结构不同。腐生葡萄球菌的这种自溶素/黏附素（Aas）似乎代表了一类新的葡萄球菌黏附素。
