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PubMed · 278973

How lac repressor recognizes lac operator.

D V Goeddel·D G Yansura·M H Caruthers
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Abstract

Nucleotide analogs were substituted for unmodified nucleotides at specific sites in the lac operator sequence by a combination of chemical and enzymatic procedures. The nitrocellulose filter assay was used to study the interactions of these modified operators with wild-type (SQ) and tight-binding (QX86) lac repressors. These studies implicate directly the 5 methyl of thymine and the 2 amino of guanine as important operator-repressor contact sites. Furthermore, when these findings are combined with published results from other laboratories, a model for the lac operator-lac repressor interaction can be derived. Two important postulates follow from this model. (i) The repressor interacts at specific and defined sites with the N7 of guanine, the 5 methyl of thymine, the 2 amino of guanine, and the central major groove of the operator. (ii) The repressor binds to one side of the operator.

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Base SequenceBinding SitesLac OperonModels, BiologicalRepressor ProteinsTranscription FactorsJournal ArticleResearch Support, U.S. Gov't, P.H.S.

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D V Goeddel, D G Yansura, M H Caruthers. 1978. How lac repressor recognizes lac operator.. https://doi.org/10.1073/pnas.75.8.3578

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