SP6 RNA-POLYMERASE STUTTERS WHEN INITIATING FROM AN AAA ... SEQUENCE
SP6 RNA-POLYMERASE STUTTERS WHEN INITIATING FROM AN AAA ... SEQUENCE
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DOI：
10.1093/nar/19.17.4669
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发表时间：
1991-09-11
影响因子：
14.9
通讯作者：
OFENGAND, J
中科院分区：
文献类型：
--
作者：
CUNNINGHAM, PR;WEITZMANN, CJ;OFENGAND, J
将大肠杆菌的16 S核糖体RNA基因置于共有和修饰的T7启动子和修饰的SP 6启动子的转录控制下。T7和SP 6聚合酶都忠实地转录每个构建体的编码序列（从+1位置开始），尽管SP 6聚合酶在AAAUUG启动时比T7聚合酶有效5倍。顺序SP 6转录物分子的一个可观部分在-1、-2、-3、-4和-5位置含有额外的腺苷。含有额外残基的转录物约占总SP 6转录产物的40-50%。将pppA 5 '端替换为pA，不会影响额外残基的性质或程度。由于插入的残基的身份不对应于模板的序列，这些额外的核苷必须由转录起始期间SP 6酶在-1至+3位置的“口吃”产生。
The 16S ribosomal RNA gene of Escherichia coli was placed under the transcriptional control of consensus and modified T7 promoters and a modified SP6 promoter. Both T7 and SP6 polymerases faithfully transcribed the coding sequence (beginning at the + 1 position) of each construct, although SP6 polymerase was five-fold more effective than T7 polymerase in initiating with the AAAUUG... sequence. An appreciable fraction of the SP6 transcript molecules contained additional adenosines in the -1, -2, -3, -4, and -5 positions. The transcripts containing additional residues constituted approximately 40-50% of the total SP6 transcription products. Neither the nature nor extent of the additional residues was affected by replacing the pppA 5'-end by pA. Since the identity of the inserted residues does not correspond to the sequence of the template, these additional nucleosides must result from 'stuttering' of the SP6 enzyme at the -1 to +3 positions during initiation of transcription.