RECOGNITION OF NUCLEOTIDE-SEQUENCES AT THE ESCHERICHIA-COLI GALACTOSE OPERON-P1 PROMOTER BY RNA-POLYMERASE
RECOGNITION OF NUCLEOTIDE-SEQUENCES AT THE ESCHERICHIA-COLI GALACTOSE OPERON-P1 PROMOTER BY RNA-POLYMERASE
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DOI：
10.1016/0378-1119(89)90496-4
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发表时间：
1989-12-14
期刊：
影响因子：
3.5
通讯作者：
BUSBY, S
中科院分区：
文献类型：
--
作者：
CHAN, B;BUSBY, S
-35区域中的特定核苷酸（nt）序列对于galP 1启动子活性不是必需的，而间隔区中的nt序列对于转录起始是必需的：nt-14处的G：C碱基对和该位置上游的序列是必需的。在缺乏这些序列的情况下，转录起始依赖于携带-35区共有六聚体序列的寡脱氧核糖核苷酸的插入。此外，为了获得最大的启动子活性，需要正好在nt-49上游的特定序列。由于galP 1没有携带类似于-35区域共有六聚体的序列，我们提出RNA聚合酶的识别通过一种不寻常的机制进行，该机制涉及间隔区的-10六聚体畸变上游的接触和nt-49上游的接触。
Specific nucleotide (nt) sequences in the -35 region are not essential for galP1 promoter activity, whereas nt sequences in the spacer region are needed for transcription initiation: a G : C base pair at nt-14 and sequences upstream from this position are necessary. In the absence of these sequences, transcription initiation is dependent on the insertion of oligodeoxyribonucleotides carrying -35 region consensus hexamer sequences. Additionally, for maximal promoter activity, specific sequences just upstream from nt -49 are required. Because galP1 carries no sequence resembling the -35 region consensus hexamer, we propose that recognition by RNA polymerase proceeds via an unusual mechanism involving contacts upstream from the -10 hexamer distortion of the spacer region and a contact upstream from nt -49.