Title
Determination of heat-shock transcription factor 2 stoichiometry at looped DNA complexes using scanning force microscopy
Date Issued
01 January 1995
Access level
open access
Resource Type
journal article
Author(s)
Wyman C.
Grotkopp E.
Nelson H.C.M.
Universidad de Oregon
Publisher(s)
Wiley-VCH Verlag
Abstract
Gene activation frequently requires an array of proteins bound to sites distal to the transcription start site. The assembly of these protein-bound sites into specialized nucleoprotein complexes is a prerequisite for transcriptional activation. Structural analysis of these higher order complexes will provide crucial information for understanding the mechanisms of gene activation. We have used both electron microscopy and scanning force microscopy to elucidate the structure of complexes formed between DNA and heat-shock transcription factor (HSF) 2, a human heat-shock transcriptional activator that binds DNA as a trimer. Electron microscopy reveals that HSF2 will bring together distant DNA sites to create a loop. We show that this association requires only the DNA binding and trimerization domains of HSF2. Metal shadowing techniques used for electron microscopy obscure details of these nucleoprotein structures. Greatly increased resolution was achieved by directly imaging the complexes in the scanning force microscope, which reveals that at least two trimers are required for the association of HSF2-bound DNA sites.
Start page
117
End page
123
Volume
14
Issue
1
Language
English
OCDE Knowledge area
Bioquímica, Biología molecular
Scopus EID
2-s2.0-0028831314
PubMed ID
Source
EMBO Journal
ISSN of the container
02614189
Sources of information: Directorio de Producción Científica Scopus