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：20
页码：9562-9565
DOI：10.1073/pnas.90.20.9562
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：The C1 protein of bacteriophage P22 binds to a unique site in the -35 region of the PRE promoter and activates transcription of the phage c2 repressor gene. This -35 target has an approximate direct repeat that overlaps the 5' end of the c1 coding region. We have isolated a single-base-pair mutation in this region that changes the PRE -35 target as well as the amino-terminal region of the C1 protein. Although the mutant C1 protein activates the mutant PRE promoter, it fails to activate the wild-type PRE promoter. This suggests that a single-base-pair mutation changes the specificities of both a protein and its target site. These studies also indicate that C1 binding to DNA is influenced by contacts made through residues near the amino terminus.
