Structure of an essential type IV pilus biogenesis protein provides insights into pilus and type II secretion systems.
Structure of an essential type IV pilus biogenesis protein provides insights into pilus and type II secretion systems.
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DOI：
10.1016/j.jmb.2012.02.041
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发表时间：
2012-05-25
影响因子：
5.6
通讯作者：
Donnenberg, Michael S.
中科院分区：
文献类型：
--
作者：
Yamagata, Atsushi;Milgotina, Ekaterina;Scanlon, Karen;Craig, Lisa;Tainer, John A.;Donnenberg, Michael S.
IV型毛（T4Ps）是细胞表面的长丝，对人类病原体的微菌落形成、组织粘附、运动、转化和毒力至关重要。肠致病性大肠杆菌形成菌毛（BFP）是一种由BfpD组装和驱动的原型T4P， BfpD是一种保守的GspE分泌超家族atp酶，由细胞膜蛋白BfpC和bfpe （gspf家族膜蛋白）持有。尽管T4P组装机制与II型分泌（T2S）系统有相似之处，但T4P组装机制的结构生物化学尚不清楚。在这里，我们报道了两域BfpC细胞质区（N-BfpC）的晶体结构，该区域负责结合atp酶BfpD和膜蛋白BfpE。N-BfpC结构在两个α/β结构域之间显示出明显的中心裂缝。尽管序列相似性可以忽略不计，但N-BfpC与细胞质T4P生物发生蛋白PilM相似。然而令人惊讶的是，N-BfpC在结构上与T2S组分EpsL有更大的相似性，它们几乎没有序列相同。胞质结构域的c端导致晶体结构中不存在的跨膜片段，N-BfpC在带正电的表面存在，最有可能与内膜相互作用，定位其中心间隙以与其他Bfp组分相互作用。表面暴露的N-BfpC残基的点突变被预测为BfpC、BfpE和BfpD之间相互作用的关键，它会破坏菌毛的生物发生，但不会阻止与BfpE和BfpD的相互作用，也不会影响BfpD的atp酶活性。这些结果阐明了T4P生物发生与T2S系统之间的关系，表明组分残基相互作用的细微变化可能对功能和发病机制产生深远影响，并表明T4P系统可能被不阻止组分组装的抑制剂破坏。
Type IV pili (T4Ps) are long cell surface filaments, essential for microcolony formation, tissue adherence, motility, transformation, and virulence by human pathogens. The enteropathogenic E. colibundle-forming pilus (BFP) is a prototypic T4P assembled and powered by BfpD, a conserved GspE secretion superfamily ATPase held by inner membrane proteins BfpC andBfpE, a GspF-family membrane protein. Although the T4P assembly machinery shares similarity with type II secretion (T2S) systems, the structural biochemistry of the T4P machine has been obscure. Here, we report the crystal structure of the two-domain BfpC cytoplasmic region (N-BfpC), responsible for binding to ATPase BfpD and membrane protein BfpE. The N-BfpC structure reveals a prominent central cleft between two α/β domains. Despite negligible sequence similarity, N-BfpC resembles PilM, a cytoplasmic T4P biogenesis protein.Yet surprisingly, N-BfpC has far greaterstructural similarity to T2S component EpsL, with which it also shares virtually no sequence identity. The C-terminus of the cytoplasmic domain, which leads to the transmembrane segment not present in the crystal structure, exits N-BfpC at a positively-charged surface that most likely interacts with the inner membrane, positioning its central cleft for interactions with other Bfp components.Point mutations in surface-exposed N-BfpC residues predicted to be critical for interactions among BfpC, BfpE and BfpD disrupt pilus biogenesis without precluding interactions with BfpE and BfpD and without affecting BfpD ATPase activity. These results illuminate the relationships between T4P biogenesis and T2S systems,imply that subtle changes in component residue interactions can have profound effects on function and pathogenesis, and suggest that T4P systems may be disrupted by inhibitors that donot preclude component assembly.
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影响因子：
3.2
作者：
Anantha, TP;Stone, KD;Donnenberg, MS
通讯作者：
Donnenberg, MS
影响因子：
5.6
作者：
Ayers, M.;Sampaleanu, L. M.;Burrows, L. L.
通讯作者：
Burrows, L. L.
影响因子：
14.9
作者：
Holm, L;Sander, C
通讯作者：
Sander, C
影响因子：
3.1
作者：
Essex-Lopresti, AE;Boddey, JA;Titball, RW
通讯作者：
Titball, RW
毒素，毒素调节的菌毛和毒素调节剂对于人类的弧菌发病机理至关重要。
影响因子：
15.3
作者：
HERRINGTON, DA;HALL, RH;LOSONSKY, G;MEKALANOS, JJ;TAYLOR, RK;LEVINE, MM
通讯作者：
LEVINE, MM