T7 RNA-POLYMERASE MUTANTS WITH ALTERED PROMOTER SPECIFICITIES
T7 RNA-POLYMERASE MUTANTS WITH ALTERED PROMOTER SPECIFICITIES
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DOI：
10.1073/pnas.90.8.3147
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发表时间：
1993-04-15
影响因子：
11.1
通讯作者：
MCALLISTER, WT
中科院分区：
文献类型：
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作者：
RASKIN, CA;DIAZ, GA;MCALLISTER, WT
T7 RNA聚合酶(RNAP)中748位的氨基酸的功能是区分启动子中-10和-11位的碱基对。我们构建了一系列在该位置具有所有可能的氨基酸取代的T7 RNAP突变体。令人惊讶的是，大多数（13/19）替换会产生活性 RNAP，并且其中许多表现出改变的启动子特异性。特异性改变的突变体 RNAP 的鉴定扩展了可用于基于噬菌体 RNAP 的转录系统的高度特异性噬菌体 RNAP 的库，并突出了序列特异性 DNA 识别的复杂性。
The amino acid at position 748 in T7 RNA polymerase (RNAP) functions to discriminate base pairs at positions -10 and -11 in the promoter. We have constructed a series of T7 RNAP mutants having all possible amino acid substitutions at this position. Surprisingly, most (13/19) substitutions result in active RNAPs, and many of these exhibit altered promoter specificities. Identification of mutant RNAPs with altered specificities expands the repertoire of highly specific phage RNAPs that are available for use in phage RNAP-based transcription systems and highlights the complexity of sequence-specific DNA recognition.