Sensitivity to the two-peptide bacteriocin lactococcin G is dependent on UppP, an enzyme involved in cell-wall synthesis
Sensitivity to the two-peptide bacteriocin lactococcin G is dependent on UppP, an enzyme involved in cell-wall synthesis
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DOI：
10.1111/mmi.12632
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发表时间：
2014-06-01
影响因子：
3.6
通讯作者：
Kristensen, Tom
中科院分区：
文献类型：
--
作者：
Kjos, Morten;Oppegard, Camilla;Kristensen, Tom
大多数细菌产生的抗菌肽（细菌素）被认为是通过受体介导的机制杀死靶细胞。然而，大多数细菌素的受体是未知的。例如，尚未鉴定出双肽细菌素（IIb类）的靶受体，其活性需要两种单独肽的联合作用。为了鉴定针对乳酸乳球菌菌株的IIb类细菌素乳球菌素G的受体，我们产生了12个乳球菌素G抗性突变体，并进行了全基因组测序以鉴定引起抗性表型的突变。值得注意的是，所有人都在uppP（巴卡）基因中或附近发生了突变，该基因编码十一异戊二烯焦磷酸酶;一种参与肽聚糖合成的膜蛋白。9个突变体在uppP基因中具有终止密码子或移码，2个在推定的调控区中具有点突变，1个在UppP中引起氨基酸取代。为了验证UppP的受体功能，当L. lactisuppP在该细菌中表达。此外，我们发现，相关的IIb类细菌素肠菌素1071也使用UppP作为受体。这里使用的方法应该广泛适用于识别其他细菌素的受体。
Most bacterially produced antimicrobial peptides (bacteriocins) are thought to kill target cells by a receptor-mediated mechanism. However, for most bacteriocins the receptor is unknown. For instance, no target receptor has been identified for the two-peptide bacteriocins (class IIb), whose activity requires the combined action of two individual peptides. To identify the receptor for the class IIb bacteriocin lactococcin G, which targets strains of Lactococcus lactis, we generated 12 lactococcin G-resistant mutants and performed whole-genome sequencing to identify mutations causing the resistant phenotype. Remarkably, all had a mutation in or near the gene uppP (bacA), encoding an undecaprenyl pyrophosphate phosphatase; a membrane protein involved in peptidoglycan synthesis. Nine mutants had stop codons or frameshifts in the uppP gene, two had point mutations in putative regulatory regions and one caused an amino acid substitution in UppP. To verify the receptor function of UppP, it was shown that growth of non-sensitive Streptococcus pneumoniae could be inhibited by lactococcin G when L. lactisuppP was expressed in this bacterium. Furthermore, we show that the related class IIb bacteriocin enterocin 1071 also uses UppP as receptor. The approach used here should be broadly applicable to identify receptors for other bacteriocins as well.