期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1993
卷号：90
期号：8
页码：3147-3151
DOI：10.1073/pnas.90.8.3147
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：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.
