SELECTIVITY OF THE ESCHERICHIA-COLI RNA-POLYMERASE E-SIGMA(38) FOR OVERLAPPING PROMOTERS AND ABILITY TO SUPPORT CRP ACTIVATION
SELECTIVITY OF THE ESCHERICHIA-COLI RNA-POLYMERASE E-SIGMA(38) FOR OVERLAPPING PROMOTERS AND ABILITY TO SUPPORT CRP ACTIVATION
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DOI：
10.1093/nar/23.5.819
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发表时间：
1995-03-11
影响因子：
14.9
通讯作者：
ISHIHAMA, A
中科院分区：
文献类型：
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作者：
KOLB, A;KOTLARZ, D;ISHIHAMA, A
一系列gal启动子突变体被用来比较两种形式的大肠杆菌rna聚合酶E sigma（38）和E sigma（70）的体外选择性。在缺乏CRP-cAMP复合物的情况下，E sigma（38）对galP1启动子表现出强烈的偏好，而E sigma（70）则优先启动galP2启动子的转录。E sigma（38）的选择性不受上游序列的性质和位置的影响，也不受合成的上游弯曲序列和-10区域之间的相位的影响，事实上，扩展-10区域突变的所有影响都可以解释，而不会引起E sigma强烈的新序列偏好（38）。最后，E sigma（38）和E sigma（70）在存在CRP-cAMP复合物的情况下启动galP1启动子的转录，并支持在几个依赖crp的启动子上直接激活cAMP-CRP。
A series of gal promoter mutants has been used to compare the in vitro selectivities of the two forms of Escherichia coliRNA polymerase, E sigma(38) and E sigma(70). In the absence of the CRP-cAMP complex, E sigma(38) shows a strong preference for the galP1 promoter, whereas E sigma(70) preferentially initiates transcription from the galP2 promoter. E sigma(38) selectivity is not affected by the nature and position of the upstream sequences or by the phasing between synthetic upstream curved sequences and the -10 regions, in fact, all effects of mutations in the extended -10 region can be accounted for without evoking strong new sequence preferences for E sigma(38). Finally, both E sigma(38) and E sigma(70) initiate transcription from the galP1 promoter in the presence of CRP-cAMP complex and support direct cAMP-CRP activation at several CRP-dependent promoters.