Structural determinants of the interaction between the Haemophilus influenzae Hap autotransporter and fibronectin.
Structural determinants of the interaction between the Haemophilus influenzae Hap autotransporter and fibronectin.
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DOI：
10.1099/mic.0.077784-0
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发表时间：
2014-06
期刊：
影响因子：
1.5
通讯作者：
Nicole A. Spahich;R. Kenjale;J. Mccann;G. Meng;T. Ohashi;H. Erickson;J. S. St. Geme
中科院分区：
文献类型：
--
作者：
Nicole A. Spahich;R. Kenjale;J. Mccann;G. Meng;T. Ohashi;H. Erickson;J. S. St. Geme
流感嗜血杆菌是一种革兰氏阴性球杆菌，通过定植在上呼吸道而引发感染。哈普是个H流感病毒丝氨酸蛋白酶自转运蛋白，在人上皮细胞测定中介导粘附、侵袭和小菌落形成，并被认为促进定殖过程。此外，Hap介导粘附到纤连蛋白、层粘连蛋白和胶原IV，细胞外基质（ECM）蛋白，其存在于呼吸道中并且可能是H.流感病毒定植。Hap负责粘附ECM蛋白的区域已经定位于Hap乘客结构域（HapS）的C-末端511 aa。在这项研究中，我们的特点是HapS和纤连蛋白之间的相互作用的结构决定因素。使用定义的纤连蛋白片段，我们确定Hap与称为FNIII（1-2）的纤连蛋白重复片段相互作用。使用定点突变，我们发现了一系列的图案在C-末端区域的HapS，有助于与纤连蛋白的相互作用。这些基序中的大多数位于HapS结构的F1和F3面，这表明F1和F3面可能负责HapS-纤连蛋白的相互作用。
Haemophilus influenzae is a Gram-negative cocco-bacillus that initiates infection by colonizing the upper respiratory tract. Hap is an H. influenzae serine protease autotransporter protein that mediates adherence, invasion and microcolony formation in assays with human epithelial cells and is presumed to facilitate the process of colonization. Additionally, Hap mediates adherence to fibronectin, laminin and collagen IV, extracellular matrix (ECM) proteins that are present in the respiratory tract and are probably important targets for H. influenzae colonization. The region of Hap responsible for adherence to ECM proteins has been localized to the C-terminal 511 aa of the Hap passenger domain (HapS). In this study, we characterized the structural determinants of the interaction between HapS and fibronectin. Using defined fibronectin fragments, we established that Hap interacts with the fibronectin repeat fragment called FNIII(1-2). Using site-directed mutagenesis, we found a series of motifs in the C-terminal region of HapS that contribute to the interaction with fibronectin. Most of these motifs are located on the F1 and F3 faces of the HapS structure, suggesting that the F1 and F3 faces may be responsible for the HapS-fibronectin interaction.