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：1977
卷号：74
期号：4
页码：1511-1515
DOI：10.1073/pnas.74.4.1511
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：The Int protein specified by bacteriophage lambda is required for the recombination event that integrates the viral DNA into the host genome at its specific attachment site. Using a DNA-binding assay, we have partially purified the Int protein and studied some of the features of its binding specificity and regulation. The DNA-binding activity is attributed to Int protein because the activity is eliminated by a nonsense mutation or a deletion in the int gene, and is rendered thermolabile by temperature-sensitive mutations in the int gene. The DNA-binding activity is specific for DNA carrying an appropriate attachment site, suggesting that Int protein directs the sequence-specific recognition essential for integrative recombination. The specific DNA-binding activity is also missing after infection by phage carrying mutations in the cII and cIII regulatory genes of lambda. This finding corroborates the conclusion from other types of experiments that regulation of the int and cI genes by cII/cIII provides for coordinate regulation of both major events of the lysogenic response, establishment of repression and insertion of viral DNA.
