Small Molecule Antibiotics Inhibit Distinct Stages of Bacterial Outer Membrane Protein Assembly.
Small Molecule Antibiotics Inhibit Distinct Stages of Bacterial Outer Membrane Protein Assembly.
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作者：
最近已经发现了几种抗菌化合物，它们可能抑制BamA的活性，BamA是在革兰氏阴性菌中组装外膜蛋白（OMP）的异源寡聚体（桶组装机器或BAM）的必需亚基，但它们的作用方式尚不清楚。为了解决这个问题，我们研究了三种抑制剂对模型E的生物发生的影响。coliOMP（EspP）的表达。我们发现darobactin有效抑制保守的C-末端序列基序（“β信号”）与BamA的相互作用，但如果在结合后阶段加入，则对组装没有影响。相反，Polyphor肽7和MRL-494抑制结合和至少一个后续组装步骤。结合先前的研究，分析了结合darobactin和Polyphor肽7 BamA在体外，我们的结果强烈表明，这两种化合物抑制BAM功能的不同的竞争和变构机制。除了提供对抗菌化合物性质的深入了解外，我们的结果还提供了直接的实验证据，支持β信号与BamA结合启动OMP膜插入的模型。
Several antibacterial compounds have recently been discovered that potentially inhibit the activity of BamA, an essential subunit of a heterooligomer (the barrel assembly machinery or BAM) that assembles outer membrane proteins (OMPs) in Gram-negative bacteria, but their mode of action is unclear. To address this issue, we examined the effect of three inhibitors on the biogenesis of a model E. coli OMP (EspP) in vivo. We found that darobactin potently inhibited the interaction of a conserved C-terminal sequence motif (the “β signal”) with BamA, but had no effect on assembly if added at a postbinding stage. In contrast, Polyphor peptide 7 and MRL-494 inhibited both binding and at least one later step of assembly. Taken together with previous studies that analyzed the binding of darobactin and Polyphor peptide 7 to BamA in vitro, our results strongly suggest that the two compounds inhibit BAM function by distinct competitive and allosteric mechanisms. In addition to providing insights into the properties of the antibacterial compounds, our results also provide direct experimental evidence that supports a model in which the binding of the β signal to BamA initiates the membrane insertion of OMPs.
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DOI：
10.1126/science.aad3460
发表时间：
2016-01-08
期刊：
Science (New York, N.Y.)
影响因子：
--
作者：
Bakelar J;Buchanan SK;Noinaj N
通讯作者：
Noinaj N
影响因子：
64.5
作者：
Doyle MT;Jimah JR;Dowdy T;Ohlemacher SI;Larion M;Hinshaw JE;Bernstein HD
通讯作者：
Bernstein HD
影响因子：
3.2
作者：
Mahoney, Tara F.;Ricci, Dante P.;Silhavy, Thomas J.
通讯作者：
Silhavy, Thomas J.
影响因子：
16.6
作者：
Iadanza, Matthew G.;Higgins, Anna J.;Schiffrin, Bob;Calabrese, Antonio N.;Brockwell, David J.;Ashcroft, Alison E.;Radford, Sheena E.;Ranson, Neil A.
通讯作者：
Ranson, Neil A.
影响因子：
64.8
作者：
Lauber F;Deme JC;Lea SM;Berks BC
通讯作者：
Berks BC