Analysis of the requirements for pilus biogenesis at the outer membrane usher and the function of the usher C-terminus.
Analysis of the requirements for pilus biogenesis at the outer membrane usher and the function of the usher C-terminus.
复制标题
外膜引座菌毛生物发生的要求及引座C末端的功能分析。
DOI：
10.1111/j.1365-2958.2006.05111.x
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发表时间：
2006
期刊：
影响因子：
--
通讯作者：
Thanassi,DavidG
中科院分区：
文献类型：
--
作者：
So,StephaneShuKin;Thanassi,DavidG
泌尿系致病性大肠埃希氏菌聚集型1型和P菌毛分别定植于膀胱和肾脏。这些菌毛是由伴侣/引导者分泌途径组装的原型结构。在这一途径中，周质伴侣与外膜(OM)引导器一起控制毛状亚单位的折叠，它们组装成毛状纤维，并将纤维分泌到细胞表面。引座员是OM中的组装和分泌平台。引座子具有不同的功能结构域，N-末端为伴侣-亚单位复合体提供初始靶点，C-末端为菌毛生物发生的后续阶段所需。在这项研究中，我们研究了在菌毛生物发生过程中引座处发生的分子相互作用以及引座器C-末端的功能。我们提供了遗传和生化证据，证明引座者在OM中作为一个复合体发挥作用，并且毛粘附素与引座者的相互作用对于引座者的生物发生至关重要。对P菌毛引导者PapC的C端截断和替换突变体的分析表明，C末端是伴侣-亚单位复合体与引导者正确结合所必需的，并且在完整菌毛的组装中起着重要作用。
Uropathogenic strains ofEscherichia coliassemble type 1 and P pili to colonize the bladder and kidney respectively. These pili are prototype structures assembled by the chaperone/usher secretion pathway. In this pathway, a periplasmic chaperone works together with an outer membrane (OM) usher to control the folding of pilus subunits, their assembly into a pilus fibre and secretion of the fibre to the cell surface. The usher serves as the assembly and secretion platform in the OM. The usher has distinct functional domains, with the N‐terminus providing the initial targeting site for chaperone–subunit complexes and the C‐terminus required for subsequent stages of pilus biogenesis. In this study, we investigated the molecular interactions occurring at the usher during pilus biogenesis and the function of the usher C‐terminus. We provide genetic and biochemical evidence that the usher functions as a complex in the OM and that interaction of the pilus adhesin with the usher is critical to prime the usher for pilus biogenesis. Analysis of C‐terminal truncation and substitution mutants of the P pilus usher PapC demonstrated that the C‐terminus is required for proper binding of chaperone–subunit complexes to the usher and plays an important role in assembly of complete pili.