The peptidoglycan-binding (PGB) Domain of the Escherichia coli Pal Protein can also Function as the PGB Domain in E. coli Flagellar Motor Protein MotB
The peptidoglycan-binding (PGB) Domain of the Escherichia coli Pal Protein can also Function as the PGB Domain in E. coli Flagellar Motor Protein MotB
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DOI：
10.1093/jb/mvp061
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发表时间：
2009-08-01
影响因子：
2.7
通讯作者：
Hommay, Michio
中科院分区：
文献类型：
--
作者：
Hizukuri, Yohei;Morton, John Frederick;Hommay, Michio
细菌鞭毛定子蛋白MOTA和MOTB形成一个复合体，被认为是通过MOTB的C端保守的肽聚糖结合(PGB)基序锚定在肽聚糖上的。为了阐明C末端区域的作用，我们进行了系统的半胱氨酸突变，并构建了嵌合的MOTB蛋白，该蛋白被肽聚糖相关脂蛋白PAL取代。虽然这种嵌合体不能恢复MOTB菌株的活力，但我们能够分离出两个能动的返回体。Pal区为F172V，MOTB区为P159L。此外，我们还尝试在大肠杆菌Pal的晶体结构中定位MOTB Cys突变。我们发现，影响运动性的MOTB突变几乎与预测的Pal的PG结合残基重叠。我们的结果表明，虽然MOTB和PAL的功能有很大的不同，但PAL的PGB区与MOTB的PGB区是可以互换的。
The bacterial flagellar stator proteins, MotA and MotB, form a complex and are thought to be anchored to the peptidoglycan by the C-terminal conserved peptidoglycan-binding (PGB) motif of MotB. To clarify the role of the C-terminal region, we performed systematic cysteine mutagenesis and constructed a chimeric MotB protein which was replaced with the peptidoglycan-associated lipoprotein Pal. Although this chimera could not restore motility to a motB strain, we were able to isolate two motile revertants. One was F172V in the Pal region and the other was P159L in the MotB region. Furthermore, we attempted to map the MotB Cys mutations in the crystal structure of Escherichia coli Pal. We found that the MotB mutations that affected motility nearly overlapped with the predicted PG-binding residues of Pal. Our results indicate that, although the functions of MotB and Pal are very different, the PGB region of Pal is interchangeable with the PGB region of MotB.