High genetic variability of the agr locus in Staphylococcus species
High genetic variability of the agr locus in Staphylococcus species
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DOI：
10.1128/jb.184.4.1180-1186.2002
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发表时间：
2002-02-01
影响因子：
3.2
通讯作者：
Lina, G
中科院分区：
文献类型：
--
作者：
Dufour, P;Jarraud, S;Lina, G
agr群体感应和信号转导系统最初在金黄色葡萄球菌中描述，其中四种不同的等位基因变体已被测序。蛋白质印迹法表明在许多其他葡萄球菌中存在同源位点，这在S。表皮葡萄球菌和表皮葡萄球菌。lugdunensis。在这项研究中，我们分离agr样基因座从一系列的葡萄球菌通过使用PCR扩增引物常见的六个公布的agr序列和包围最可变的区域，与群体感应特异性。从34个葡萄球菌种或亚种中的14个获得阳性扩增。扩增子的序列鉴定出24种不同的变体，其表现出广泛的序列差异，在多重比对中仅10%的核苷酸绝对保守。这种变异性涉及参与群体感应和信号转导的所有三个开放阅读框架。然而，这些变体保留了几个蛋白质特征，包括自诱导肽的保守半胱氨酸残基，除了S。中间体的鸽子起源，其中含有丝氨酸的地方半胱氨酸在这个位置。我们讨论的行动模式和agr基因座的分子进化的基础上新确定的序列之间的比较假说。
The agr quorum-sensing and signal transduction system was initially described in Staphylococcus aureus, where four distinct allelic variants have been sequenced. Western blotting suggests the presence of homologous loci in many other staphylococci, and this has been confirmed for S. epidermidis and S. lugdunensis. In this study we isolated agr-like loci from a range of staphylococci by using PCR amplification from primers common to the six published agr sequences and bracketing the most variable region, associated with quorum-sensing specificity. Positive amplifications were obtained from 14 of 34 staphylococcal species or subspecies tested. Sequences of the amplicons identified 24 distinct variants which exhibited extensive sequence divergence with only 10% of the nucleotides absolutely conserved on multiple alignment. This variability involved all three open reading frames involved in quorum sensing and signal transduction. However, these variants retained several protein signatures, including the conserved cysteine residue of the autoinducing peptide, with the exception of S. intermedius of pigeon origin, which contained a serine in place of cysteine at this position. We discuss hypotheses on the mode of action and the molecular evolution of the agr locus based on comparisons between the newly determined sequences.