An electrostatic interaction between BlpC and BlpH dictates pheromone specificity in the control of bacteriocin production and immunity in Streptococcus pneumoniae.
An electrostatic interaction between BlpC and BlpH dictates pheromone specificity in the control of bacteriocin production and immunity in Streptococcus pneumoniae.
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BlpC 和 BlpH 之间的静电相互作用决定了控制肺炎链球菌细菌素产生和免疫的信息素特异性。
DOI：
10.1128/jb.02432-14
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发表时间：
2015
影响因子：
3.2
通讯作者：
Dawid,Suzanne
中科院分区：
文献类型：
--
作者：
Pinchas,MarisaD;LaCross,NathanC;Dawid,Suzanne
肺炎链球菌的斑点分泌和调节细菌素，细菌素在人类鼻咽中既介导种内竞争又介导种间竞争。PH基因有四个主要的等位基因，当与四种不同的多肽信息素(BlpC)之一结合时，它编码负责激活斑点的受体。BLPH值的等位基因变异可能是因为需要限制竞争菌株之间的串扰。BlpH蛋白序列的多态分布在整个序列中，这使得识别多肽结合部位变得困难。为了确定决定信息素特异性的信息素结合位点，我们表征了四个主要的变种和两个自然发生的blpH嵌合版本，其中重组事件似乎已将两个不同的blpH等位基因连接在一起。利用这些等位基因变体、一系列实验室产生的嵌合pH等位基因以及受体和多肽的定点突变，我们证明了BlpC与某些BlpH类型的结合涉及BlpC的相反电荷残基与BlpH的第一跨膜结构域之间的静电相互作用。在第二个细胞外环中发现了一个额外的识别位点。我们确定了自然产生的BlpH类型，这些类型能够对多种BlpC类型做出反应；然而，这种特异性的变化导致总体敏感度的相应下降。选择这些自然重组事件可能是为了平衡感受细菌素分泌邻居的需要和在低密度下打开细菌素生产的需要。重要的是，细菌利用群体感应来优化基因表达，以适应当地的细菌密度和扩散速度。为了防止邻近菌株对群体感应信号的拦截，单一物种的基因组通常编码菌株特有的信号/受体对。肺炎链球菌中驱动细菌素分泌的菌斑受群体感应控制，涉及信号/受体对BlpC/BlpH的相互作用。我们发现肺炎球菌群体可以分为几个不同的BlpC/BlpH对；然而，也有一些自然产生的嵌合受体可以与一种以上的BlpC类型结合。这种扩大的特异性的权衡是整体受体敏感性的丧失。这表明，在一定条件下，信号拦截的优势可以胜过自我感应的要求。
Theblplocus of Streptococcus pneumoniae secretes and regulates bacteriocins, which mediate both intra- and interspecific competition in the human nasopharynx. There are four major alleles of the geneblpH, which encodes the receptor responsible for activating theblplocus when bound to one of four distinct peptide pheromones (BlpC). The allelic variation ofblpHis presumably explained by a need to restrict cross talk between competing strains. The BlpH protein sequences have polymorphisms distributed throughout the sequence, making identification of the peptide binding site difficult to predict. To identify the pheromone binding sites that dictate pheromone specificity, we have characterized the four major variants and two naturally occurring chimeric versions ofblpHin which recombination events appear to have joined two distinctblpHalleles together. Using these allelic variants, a series of laboratory-generated chimericblpHalleles, and site-directed mutants of both the receptor and peptide, we have demonstrated that BlpC binding to some BlpH types involves an electrostatic interaction between the oppositely charged residues of BlpC and the first transmembrane domain of BlpH. An additional recognition site was identified in the second extracellular loop. We identified naturally occurring BlpH types that have the capacity to respond to more than one BlpC type; however, this change in specificity results in a commensurate drop in overall sensitivity. These natural recombination events were presumably selected for to balance the need to sense bacteriocin-secreting neighbors with the need to turn on bacteriocin production at a low density.IMPORTANCEBacteria use quorum sensing to optimize gene expression to accommodate for local bacterial density and diffusion rates. To prevent interception of quorum-sensing signals by neighboring strains, the genomes of single species often encode strain-specific signal/receptor pairs. Theblplocus in Streptococcus pneumoniae that drives bacteriocin secretion is controlled by quorum sensing that involves the interaction of the signal/receptor pair BlpC/BlpH. We show that the pneumococcal population can be divided into several distinct BlpC/BlpH pairs; however, there are examples of naturally occurring chimeric receptors that can bind to more than one BlpC type. The trade-off for this broadened specificity is a loss of overall receptor sensitivity. This suggests that under certain conditions, the advantage of signal interception can trump the requirements for self-induction.
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DOI：
--
发表时间：
1965
期刊：
影响因子：
--
作者：
M. Lamm;D. Neville
通讯作者：
D. Neville
奎纳克林与 DNA 相互作用的协同性和离子效应分析
影响因子：
2.9
作者：
W. Wilson;I. Lopp
通讯作者：
I. Lopp
DOI：
10.1111/j.1432-1033.1975.tb04137.x
发表时间：
1975-01-01
期刊：
EUROPEAN JOURNAL OF BIOCHEMISTRY
影响因子：
--
作者：
MULLER, W;CROTHERS, DM
通讯作者：
CROTHERS, DM
吖啶橙与 RNA 的固体复合物的发光。
DOI：
10.1002/cyto.990020402
发表时间：
1982
期刊：
Cytometry
影响因子：
--
作者：
Kapuscinski,J;Darzynkiewicz,Z;Melamed,MR
通讯作者：
Melamed,MR
影响因子：
5.8
作者：
KAPUSCINSKI, J;DARZYNKIEWICZ, Z
通讯作者：
DARZYNKIEWICZ, Z