Structure and function of RNA thermometers

RNA温度计控制许多细菌热休克和毒力基因的翻译启动，以响应温度的升高。它们位于5‘-非翻译区(5’-UTR)，该区域折叠成一个复杂的结构，在低温下阻止进入Shine-Dalgarno(SD)序列。温度升高到37°C(毒力基因)或更高(热激基因)会导致该结构的融化，使SD序列可用于30S核糖体。我们正在研究三种不同类型的RNA温度计的个体成员，即所谓的ROSE(热休克基因表达抑制)、FourU(四个尿苷)和Cytherm(蓝藻温度计)元素。未来研究的主要目的是证明这些RNA温度计在细菌应激和毒力反应中的生理重要性。其他目标是定义最低限度的玫瑰元素，并仔细检查病原微生物的四个U温度计。此外，我们计划研究来自嗜热菌的潜在的RNA温度计。已经预测到，通过融化以外的机制作用的RNA温度计位于冷休克基因和金黄色葡萄球菌毒力基因的上游。将研究这些候选人的结构和功能。

RNA thermometers control translation initiation of many bacterial heat shock and virulence genes in response to elevated temperatures. They are located in the 5’-untranslated region (5’-UTR), which folds into a complex structure that blocks access to the Shine-Dalgarno (SD) sequence at low temperatures. A temperature upshift to 37 °C (virulence genes) or higher (heat shock genes) induces melting of that structure making the SD sequence available to the 30S ribosome. We are studying individual members of three different classes of RNA thermometers, socalled ROSE (Repression Of heat Shock gene Expression), fourU (four uridines) and Cyotherm (cyanobacterial thermometer) elements. The major aim of future studies is to demonstrate the physiological importance of these RNA thermometers in the bacterial stress and virulence response. Other goals are to define a minimal ROSE element and to closely examine fourU thermometers from pathogenic microorganisms. In addition, we plan to investigate potential RNA thermometers from thermophilic bacteria. RNA thermometers that act by mechanisms other than melting have been predicted upstream of cold shock genes and a virulence gene from Staphylococcus aureus. The structure and function of these candidates will be studied.