Hinge-helix formation and DNA bending in various lac repressor-operator complexes.

Content Provider	Semantic Scholar
Author	Noordman, A. M. Wechselberger, Rainer W. Brink, Nico W. Van Den Boelens, Rolf
Copyright Year	1999
Abstract	The hinge-region of the lac repressor plays an important role in the models for induction and DNA looping in the lac operon. When lac repressor is bound to a tight-binding symmetric operator, this region forms an alpha-helix that induces bending of the operator. The presence of the hinge-helices is questioned by previous data that suggest that the repressor does not bend the wild-type operator. We show that in the wild-type complex the hinge-helices are formed and the DNA is bent, similar to the symmetric complex. Furthermore, our data show differences in the binding of the DNA binding domains to the half-sites of the wild-type operator and reveal the role of the central base-pair of the wild-type operator in the repressor-operator interaction. The differences in binding to the operator half-sites are incorporated into a model that explains the relative affinities of the repressor for various lac operator sequences that contain left and right half-sites with different spacer lengths.
File Format	PDF HTM / HTML
Alternate Webpage(s)	http://embojnl.embopress.org/content/embojnl/18/22/6472.full.pdf
PubMed reference number	10562559v1
Volume Number	18
Issue Number	22
Journal	The EMBO journal
Language	English
Access Restriction	Open
Subject Keyword	Bending - Changing basic body position Hinge (physical object) Hinge Device Component Lac Operon Lac Repressors Transcription Repressor/Corepressor dna binding
Content Type	Text
Resource Type	Article