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：1991
卷号：88
期号：13
页码：5699-5703
DOI：10.1073/pnas.88.13.5699
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：The relative binding affinities of Mnt protein from bacteriophage P22 are determined for each possible base pair at position 17 of the operator. These are determined from the partitioning of randomized operators into bound and unbound fractions; quantitation is provided by restriction enzyme analysis. Mnt protein is found to have an unusual specificity at this position: a C.G base pair (the wild-type operator) has the highest affinity, a G.C base pair has the lowest affinity, and both orientations of A.T base pairs are intermediate and nearly equivalent. A specific binding constant and specific binding free energy are defined and shown to be directly related to the information content of the operator sequences bound to the protein, taking into account the quantitative differences in binding affinities.
