Grossman A D, Erickson J W, Gross C A
Cell. 1984 Sep;38(2):383-90. doi: 10.1016/0092-8674(84)90493-8.
The htpR gene of E. coli encodes a positive regulator of the heat-shock response. We have fused the htpR gene to the inducible PL promoter of phage lambda. Overproduction of HtpR following a temperature upshift resulted in the overexpression of heat-shock proteins. We describe the purification and initial in vitro characterization of the factor controlling expression of heat-shock genes. The factor was the 32 kd htpR gene product. In vitro, a mixture of HtpR and core RNA polymerase initiated transcription at heat-shock promoters. The sigma factor encoded by rpoD was not required for this reaction. Therefore, HtpR is a sigma factor that promotes transcription initiation at heat-shock promoters. We propose that htpR be renamed rpoH and that the gene product be called sigma-32.
大肠杆菌的htpR基因编码一种热休克反应的正调控因子。我们已将htpR基因与噬菌体λ的可诱导PL启动子融合。温度升高后HtpR的过量产生导致热休克蛋白的过表达。我们描述了控制热休克基因表达的因子的纯化及初步体外特性分析。该因子是32kd的htpR基因产物。在体外，HtpR与核心RNA聚合酶的混合物在热休克启动子处起始转录。此反应不需要rpoD编码的σ因子。因此，HtpR是一种在热休克启动子处促进转录起始的σ因子。我们建议将htpR重新命名为rpoH，其基因产物称为σ-32。
