Characterization of the genetic locus encoding Haemophilus influenzae type b surface fibrils.
Characterization of the genetic locus encoding Haemophilus influenzae type b surface fibrils.
复制标题
编码 b 型流感嗜血杆菌表面原纤维的遗传位点的表征。
DOI：
10.1128/jb.178.21.6281-6287.1996
复制
发表时间：
1996
影响因子：
3.2
通讯作者：
Barenkamp,SJ
中科院分区：
文献类型：
--
作者：
StGeme3rd,JW;Cutter,D;Barenkamp,SJ
流感嗜血杆菌是一种常见的革兰氏阴性病原体，通过定植于上呼吸道上皮来引发感染。在之前的工作中，我们报道了 B 型流感嗜血杆菌表达短而薄的表面原纤维的位点的分离，并提供了表面原纤维促进与人上皮细胞附着的证据。在本研究中，我们确定原纤维基因座由一个长的开放阅读框组成，称为hsf，它编码一种分子量约为240 kDa的蛋白质（Hsf）。 hsf 产物的衍生氨基酸序列与最近鉴定的不可分型流感嗜血杆菌粘附素（称为 Hia）有 81% 的相似性和 72% 的同一性。在一组八个培养细胞系的实验中，发现 Hsf 和 Hia 蛋白具有相同的结合特异性，表明 hsf 和 hia 是同一基因座的等位基因。 Southern 分析和诱变研究强化了这一结论。进一步的研究表明，hsf 同源物在封装的流感嗜血杆菌菌株中普遍存在，并且也存在于不可分型的嗜血杆菌菌株的子集中。我们推测hsf基因产物在流感嗜血杆菌呼吸道定植过程中发挥重要作用。
Haemophilus influenzae is a common gram-negative pathogen that initiates infection by colonizing the upper respiratory tract epithelium. In previous work, we reported the isolation of a locus involved in expression of short, thin surface fibrils by H. influenzae type b and presented evidence that surface fibrils promote attachment to human epithelial cells. In the present study, we determined that the fibril locus is composed of one long open reading frame, designated hsf, which encodes a protein (Hsf) with a molecular mass of approximately 240 kDa. The derived amino acid sequence of the hsf product demonstrated 81% similarity and 72% identity to a recently identified nontypeable H. influenzae adhesin referred to as Hia. In experiments with a panel of eight cultured cell lines, the Hsf and Hia proteins were found to confer the same binding specificities, suggesting that hsf and hia are alleles of the same locus. Southern analysis and mutagenesis studies reinforced this conclusion. Further investigation revealed that an hsf homolog is ubiquitous among encapsulated H. influenzae strains and is present in a subset of nontypeable Haemophilus strains as well. We speculate that the hsf gene product plays an important role in the process of respiratory tract colonization by H. influenzae.