Streptococcus mutans (S. mutans) is a serious microbe causing dental caries. Mutacin IV is an effective bacteriocin produced by S. mutans to antagonize numerous non-mutans streptococcal species. However, the posttranscriptional regulation of mutacin IV remains unclear. This study aimed to analyze the effect of small RNA srn225147 on mutacin IV. The functional prediction suggested that srn225147 is involved in the production of mutacin IV, an important secondary metabolite. According to RNAhybrid and RNAPredator prediction, the mutacin IV formation-associated gene comD is a target of srn225147. We further analyzed the roles of srn225147 and comD in 20 S. mutans clinical strains with high production of mutacin IV (High-IV group) and lacking mutacin IV (None-IV group). Levels of comD expression were significantly higher in the High-IV group, whereas the Non-IV group showed relatively higher expression of srn225147, with a negative correlation observed between srn225147 and comD. Moreover, compared to the mimic negative control (NC) group, comD expression was decreased at 400-fold srn225147 overexpression but increased at approximately 1400-fold overexpression. Although the production of mutacin IV in the 1400-fold change srn225147 mimic group was larger than that in the 400-fold change mimic group, there was no significant difference in the production of mutacin IV between the srn225147 mimic group and mimic NC group. These results indicate that srn225147 has a two-way regulation effect on the expression of comD but that its regulation in the production of mutacin IV is weak.

中文翻译：

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洞察小RNA srn225147对变形链球菌突变素IV的影响。

变形链球菌（变形链球菌）是一种引起龋齿的严重微生物。突变蛋白IV是由变形链球菌产生的有效细菌素，可拮抗许多非变形链球菌物种。但是，突变蛋白IV的转录后调控仍不清楚。本研究旨在分析小RNA srn225147对诱变蛋白IV的作用。功能预测表明，srn225147参与了重要的次生代谢产物诱变剂IV的产生。根据RNAhybrid和RNAPredator预测中，变异菌肽IV的形成相关基因的comD是一个目标srn225147。我们进一步分析了srn225147和的comD在20个变形链球菌临床菌株具有高的生产变异菌肽IV（高IV组）和缺乏变异菌肽IV（无-IV组）。的水平的comD表达均高IV组显著更高，而非IV组显示出相对较高的表达srn225147，与之间观察到的负相关srn225147和的comD。此外，相对于模拟物阴性对照（NC）基团，的comD表达在400倍的降低srn225147过表达，但在约1400倍的过表达增加了。虽然诱变剂IV的产量在1400倍变化srn225147模拟组大于400倍变化模拟组，srn225147模拟组和NC组之间诱变素IV的产生没有显着差异。这些结果表明，srn225147对表达的双向调节作用的comD但其在生产变异菌肽IV的调节是弱。