Structural basis of DNA binding and autoinhibition for the eukaryotic transcription factor ETS-1

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Publication Type dissertation
School or College School of Medicine
Department Oncological Sciences
Author Petersen, Jeannine Marie
Title Structural basis of DNA binding and autoinhibition for the eukaryotic transcription factor ETS-1
Date 1996-08
Description The ets family of transcription factors represents a paradox in the study of DNA binding proteins. How can regulatory proteins that share the same DNA binding properties exert the distinguishable effects necessary to execute gene regulation? As a framework for addressing this question, the molecular basis of DNA binding for Ets-1, the founding member of the ets family, was determined. Two N-terminal deletion polypeptides of Ets-1 that retained either DNA binding (DeltaN331) or DNA binding and autoinhibition (DeltaN280) were utilized for these studies. Determination of the nuclear magnetic resonance (NMR) secondary structure for the Ets-1 DNA binding domain (ETS domain) classified the ets proteins into a structural family of DNA binding proteins termed the winged helix-turn-helix (wHTH) superfamily. Tertiary structure analysis of the Ets-1 ETS domain confirmed the wHTH DNA binding motif and showed that the ETS domain is composed of a three-helix bundle packed against a four-stranded antiparallel beta-sheet. A helix-turn-helix DNA binding motif is found within the three-helix bundle. Insight into the mode of DNA binding utilized by Ets-1 and other ets proteins was obtained by comparison to previously described cocrystal structures for wHTH proteins. Additional insights into ets protein DNA binding specificity come from structural studies of Ets-1 autoinhibition. Quantitative DNA binding assays defined a minimal region required for Ets-1 DNA binding inhibition. Thermal denaturation studies demonstrated that the functions of inhibition and DNA binding are coupled within a single structural domain. NMR secondary structure analysis confirmed this finding and showed that the Ets-1 inhibitory domain is composed of four alpha helices; two alpha helices in the N-terminal inhibitory region, one alpha helix in the C-terminal inhibitory region, and helix one in the ETS domain. Furthermore, these studies demonstrated that the alpha helices within the N- and C-terminal inhibitory regions of Ets-1 are structurally coupled to each other and to the ETS domain. Upon DNA binding, a unique conformational change involving unfolding of an alpha helix within the N-terminal inhibitory region was observed. This provided evidence that disruption of the inhibitory module occurs on DNA binding. A model is presented whereby interactions with a protein partner could serve to stabilize the de-repressed Ets-1 conformation. Thus, specificity of binding for members of the ets family that display autoinhibition of DNA binding could be determined via interaction with a protein partner. These findings provide important insight into the molecular basis of cooperative partnerships between DNA binding proteins and the conformational changes that regulate transcription factor function.
Type Text
Publisher University of Utah
Subject Gene Expression Regulation; Eukaryotic Cells
Subject MESH DNA-Binding Proteins; Transcription, Genetic
Dissertation Institution University of Utah
Dissertation Name PhD
Language eng
Relation is Version of Digital reproduction of "Structural basis of DNA binding and autoinhibition for the eukaryotic transcription factor ETS-1." Spencer S. Eccles Health Sciences Library. Print version of "Structural basis of DNA binding and autoinhibition for the eukaryotic transcription factor ETS-1." available at J. Willard Marriott Library Special Collection. QP6.5 1996 .P48.
Rights Management © Jeannine Marie Petersen.
Format Medium application/pdf
Format Extent 4,538,346 bytes
Identifier undthes,5193
Source Original: University of Utah Spencer S. Eccles Health Sciences Library (no longer available).
Funding/Fellowship Fellowship from the Development Biology Training Grant 1T
Master File Extent 4,538,391 bytes
ARK ark:/87278/s6cf9rzg
Setname ir_etd
Date Created 2012-04-24
Date Modified 2012-04-24
ID 191200
Reference URL