| Literature DB >> 3186699 |
N Lehming1, J Sartorius, S Oehler, B von Wilcken-Bergmann, B Müller-Hill.
Abstract
Exchanges in positions 1 and 2 of the putative recognition helix allow lac repressor to bind to ideal lac operator variants in which base pair 4 has been replaced. We show here that an Arg-22----Asn exchange in position 6 of the putative recognition helix of lac repressor abolishes lac repressor binding to ideal lac operator. This lac repressor variant, however, binds to a variant of the ideal lac operator 5' TTTGAGCGCTCAAA 3' in which the original G.C of position 6 has been replaced by T.A. This result and our previous data confirm our suggestion that the N terminus of the recognition helix of lac repressor enters the major groove close to the center of symmetry of lac operator and that its C terminus leaves the major groove further away from the center of symmetry. The consequences of this model are discussed in regard to various phage and bacterial repressor operator systems.Entities:
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Year: 1988 PMID： 3186699 PMCID： PMC282330 DOI： 10.1073/pnas.85.21.7947
Source DB: PubMed Journal: Proc Natl Acad Sci U S A ISSN： 0027-8424 Impact factor: 11.205