Lmb, a protein with similarities to the LraI adhesin family, mediates attachment of Streptococcus agalactiae to human laminin
Lmb, a protein with similarities to the LraI adhesin family, mediates attachment of Streptococcus agalactiae to human laminin
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DOI：
10.1128/iai.67.2.871-878.1999
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发表时间：
1999-02-01
影响因子：
3.1
通讯作者：
Podbielski, A
中科院分区：
文献类型：
--
作者：
Spellerberg, B;Rozdzinski, E;Podbielski, A
无乳链球菌是新生儿败血症和脑膜炎的主要原因。粘附于细胞外基质蛋白被认为是感染发病机制中的重要因素，但该过程的遗传决定因素在很大程度上仍然未知。我们确定并测序了一个基因，该基因编码一种推定的脂蛋白，该脂蛋白与链球菌LraI蛋白家族具有显着的同源性。该基因座的突变体被证明对固定化的人层粘连蛋白具有显著降低的粘附性。该基因的核苷酸序列随后被命名为Imb（层粘连蛋白结合），并显示存在于所有常见的S血清型中。无乳。探讨Lmb在S.为了使无乳野生型菌株与层粘连蛋白结合，从大肠杆菌中克隆、表达并纯化了在C末端具有六个连续组氨酸残基的重组Lmb蛋白。重组Lmb的固定化层粘连蛋白的预孵育显着降低了粘附的野生型菌株O90R层粘连蛋白。这些结果表明Lmb介导了S.无乳症的人层粘连蛋白，这可能是必不可少的细菌定植受损的上皮细胞和易位的细菌进入血流。
Streptococcus agalactiae is a leading cause of neonatal sepsis and meningitis. Adherence to extracellular matrix proteins is considered an important factor in the pathogenesis of infection, but the genetic determinants of this process remain largely unknown. We identified and sequenced a gene which codes for a putative lipoprotein that exhibits significant homology to the streptococcal LraI protein family. Mutants of this locus were demonstrated to have substantially reduced adherence to immobilized human laminin. The nucleotide sequence of the gene was subsequently designated Imb (laminin binding) and shown to be present in all of the common serotypes of S. agalactiae. To determine the role of Lmb in the adhesion of S. agalactiae wild-type strains to laminin, a recombinant Lmb protein harboring six consecutive histidine residues at the C terminus was cloned, expressed, and purified from Escherichia coli. Preincubation of immobilized laminin with recombinant Lmb significantly reduced adherence of the wild-type strain O90R to laminin. These results indicate that Lmb mediates the attachment of S. agalactiae to human laminin, which may be essential for the bacterial colonization of damaged epithelium and translocation of bacteria into the bloodstream.