Role of the Escherichia coli SbmA in the antimicrobial activity of proline-rich peptides
Role of the Escherichia coli SbmA in the antimicrobial activity of proline-rich peptides
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DOI：
10.1111/j.1365-2958.2007.05903.x
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发表时间：
2007-10-01
影响因子：
3.6
通讯作者：
Scocchi, Marco
中科院分区：
文献类型：
--
作者：
Mattiuzzo, Maura;Bandiera, Antonella;Scocchi, Marco
与许多抗微生物肽相反，富含脯氨酸的抗微生物肽组的成员通过非溶解机制杀灭革兰氏阴性菌。几条证据表明，它们被内化到细菌中，其活性通过与未知细胞组分的相互作用介导。为了鉴定这种相互作用，我们选择了对富含脯氨酸的Bac 7（1-35）肽具有抗性的诱变大肠杆菌克隆，并分析了负责赋予抗性的基因，其产物因此可能参与肽的作用模式。我们分离了一些基因组区域轴承这样的基因，特别是一个编码SbmA，内膜蛋白预测是ABC转运蛋白的一部分。大肠携带sbmA点突变的大肠杆菌菌株，以及其他sbmA无效突变体，事实上显示出对几种富含脯氨酸的肽的抗性，但对代表性的膜溶解肽没有抗性。使用荧光标记的Bac 7（1-35）证实了抗性与降低的内化肽的能力相关，表明细菌蛋白SbmA对于真核生物来源的富含脯氨酸的抗微生物肽的转运和易感性是必需的。
In contrast to many antimicrobial peptides, members of the proline-rich group of antimicrobial peptides inactivate Gram-negative bacteria by a non-lytic mechanism. Several lines of evidence indicate that they are internalized into bacteria and their activity mediated by interaction with unknown cellular components. With the aim of identifying such interactors, we selected mutagenized Escherichia coli clones resistant to the proline-rich Bac7(1-35) peptide and analysed genes responsible for conferring resistance, whose products may thus be involved in the peptide's mode of action. We isolated a number of genomic regions bearing such genes, and one in particular coding for SbmA, an inner membrane protein predicted to be part of an ABC transporter. An E. coli strain carrying a point mutation in sbmA, as well as other sbmA-null mutants, in fact showed resistance to several proline-rich peptides but not to representative membranolytic peptides. Use of fluorescently labelled Bac7(1-35) confirmed that resistance correlated with a decreased ability to internalize the peptide, suggesting that a bacterial protein, SbmA, is necessary for the transport of, and for susceptibility to, proline-rich antimicrobial peptides of eukaryotic origin.