IDENTIFICATION OF THE SIGMA-E SUBUNIT OF ESCHERICHIA-COLI RNA-POLYMERASE - A 2ND ALTERNATE SIGMA-FACTOR INVOLVED IN HIGH-TEMPERATURE GENE-EXPRESSION
IDENTIFICATION OF THE SIGMA-E SUBUNIT OF ESCHERICHIA-COLI RNA-POLYMERASE - A 2ND ALTERNATE SIGMA-FACTOR INVOLVED IN HIGH-TEMPERATURE GENE-EXPRESSION
复制标题
DOI：
10.1101/gad.3.9.1462
复制
发表时间：
1989-09-01
影响因子：
10.5
通讯作者：
GROSS, CA
中科院分区：
文献类型：
--
作者：
ERICKSON, JW;GROSS, CA
大肠杆菌的RPOH基因编码.sigma.32，32-kd .sigma.因子，负责热休克基因的热诱导转录。 RPOH至少从三个启动子转录。这些启动子中的两个是由含有.sigma.70的RNA聚合酶识别的。我们纯化了负责识别第三RPOH启动子（RPOH P3）的因素，并将其识别为含有Anovel .Sigma.-Factor的RNA聚合酶，其明显MR为24,000。我们称之为.sigma.e的这个新的.sigma。与已知的.sigma不同。分子量和启动子特异性的因素。 .sigma.e Holoenzys不会识别我们测试的32个控制启动子的.sigma.70-或.sigma.sigma.sigma.sigma.70-或.sigma，但它确实会抄录HTRA基因，这是温度> 42.高度的生存力所必需的。 C. .sigma.e的体内作用尚不清楚。来自.sigma.e控制的RPOH P3和HTRA启动子的转录本在非常高的温度下最丰富，这表明.sigma.e Holoenzyme可能会转录第二组在高温下或在高温下或IN中涉及的热诱导基因温耐剂。
The rpoH gene of Escherichia coli encodes .sigma.32, the 32-kD .sigma.-factor responsible for the heat-inducible transcription of the heat shock genes. rpoH is transcribed from at least three promoters. Two of these promoters are recognized by RNA polymerase containing .sigma.70, the predominant .sigma.-factor. We purified the factor responsible for recognizing the third rpoH promoter (rpoH P3) and identified it as RNA polymerase containing anovel .sigma.-factor with an apparent Mr of 24,000. This new .sigma., which we call .sigma.E, is distinct from the known .sigma. factors in molecular weight and promoter specificity. .sigma.E holoenzymes will not recognize the .sigma.70- or .sigma.32-controlled promoters we tested, but it does transcribe the htrA gene, which is required for viability at temperatures > 42.degree. C. The in vivo role of .sigma.E is not known. The transcripts from the .sigma.E-controlled rpoH P3 and htrA promoters are most abundant at very high temperature, suggesting the .sigma.E holoenzyme may transcribe a second set of heat-inducible genes that are involved in growth at high temperature or in thermotolerance.