Common architecture of the flagellar type III protein export apparatus and F- and V-type ATPases
Common architecture of the flagellar type III protein export apparatus and F- and V-type ATPases
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DOI：
10.1038/nsmb.1977
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发表时间：
2011-03-01
影响因子：
16.8
通讯作者：
Namba, Keiichi
中科院分区：
文献类型：
--
作者：
Ibuki, Tatsuya;Imada, Katsumi;Namba, Keiichi
形成细菌鞭毛的蛋白质通过鞭毛特异性蛋白质输出装置（III型蛋白质分泌系统的一个家族）通过生长鞭毛的中央通道移位到其远端。FliI和FliJ是该装置的可溶性组分。FliI是一种ATP酶，与FoF 1-ATP合酶的α和β亚基具有广泛的结构相似性。FliJ对出口至关重要，但其功能仍不清楚。在这里，我们表明，来自沙门氏菌肠血清型鼠伤寒沙门氏菌的FliJ的结构是非常相似的FoF 1-ATP合酶的γ亚基的双链α-螺旋卷曲螺旋的一部分，FliJ促进FliI六聚体环的形成结合到环的中心。这些结果表明，III型蛋白质输出系统和F-和V-型ATP酶有着相似的机制和进化关系。
The proteins that form the bacterial flagellum are translocated to its distal end through the central channel of the growing flagellum by the flagellar-specific protein export apparatus, a family of the type III protein secretion system. FliI and FliJ are soluble components of this apparatus. FliI is an ATPase that has extensive structural similarity to the alpha and beta subunits of FoF1-ATP synthase. FliJ is essential for export, but its function remains obscure. Here we show that the structure of FliJ derived from Salmonella enterica serovar Typhimurium is remarkably similar to that of the two-stranded alpha-helical coiled-coil part of the gamma subunit of FoF1-ATP synthase and that FliJ promotes the formation of FliI hexamer rings by binding to the center of the ring. These results suggest that the type III protein export system and F- and V-type ATPases share a similar mechanism and an evolutionary relationship.