Contribution of chloride channel permease to fluoride resistance in Streptococcus mutans
Contribution of chloride channel permease to fluoride resistance in Streptococcus mutans
复制标题
DOI：
10.1093/femsle/fnw101
复制
发表时间：
2016-06-01
影响因子：
2.1
通讯作者：
Hanada, Nobuhiro
中科院分区：
文献类型：
--
作者：
Murata, Takatoshi;Hanada, Nobuhiro
编码氟化物转运体的基因已经在细菌和古细菌物种中被鉴定出来。龋齿变异链球菌的基因组序列表明存在一种假定的氟化物转运体，即氯离子通道渗透酶。该基因的两个同源物（GenBank位点标记SMU_1290c和SMU_1289c）串联存在于变形链球菌的基因组中。本研究的目的是确定氯离子通道渗透是否有助于抗氟性。我们构建了SMU_1290c-和smu_1289c敲除的S. mutans UA159菌株。我们还构建了一个缺乏这两个基因的双敲除菌株。将SMU_1290c或SMU_1289c转化为氟化物转运体中断的大肠杆菌菌株。所有菌株在适当条件下加氟和不加氟培养，并评价其对氟的耐药性。所有三种基因敲除突变链球菌菌株对氟化钠的抗性都低于野生型菌株。野生型和双敲除菌株对其他卤化钠的抗性没有显著变化。SMU_1290c和SMU_1289c转化均可使氟化物转运体中断的大肠杆菌细胞免于氟化物毒性。我们得出结论，氯离子通道渗透有助于变形链球菌的氟抗性。
Genes encoding fluoride transporters have been identified in bacterial and archaeal species. The genome sequence of the cariogenic Streptococcus mutans bacteria suggests the presence of a putative fluoride transporter, which is referred to as a chloride channel permease. Two homologues of this gene (GenBank locus tags SMU_1290c and SMU_1289c) reside in tandem in the genome of S. mutans. The aim of this study was to determine whether the chloride channel permeases contribute to fluoride resistance. We constructed SMU_1290c- and SMU_1289c-knockout S. mutans UA159 strains. We also constructed a double-knockout strain lacking both genes. SMU_1290c or SMU_1289c was transformed into a fluoride transporter-disrupted Escherichia coli strain. All bacterial strains were cultured under appropriate conditions with or without sodium fluoride, and fluoride resistance was evaluated. All three gene-knockout S. mutans strains showed lower resistance to sodium fluoride than did the wild-type strain. No significant changes in resistance to other sodium halides were recognized between the wild-type and double-knockout strains. Both SMU_1290c and SMU_1289c transformation rescued fluoride transporter-disrupted E. coli cell from fluoride toxicity. We conclude that the chloride channel permeases contribute to fluoride resistance in S. mutans.