Enlighten
Research publications by members of the University of Glasgow
home > services > Enlighten

Calorimetric studies of the energetics of protein—DNA interactions in the E. coli methionine repressor (MetJ) system

Cooper, A., Mcalpine, A., and Stockley, P. G. (1994) Calorimetric studies of the energetics of protein—DNA interactions in the E. coli methionine repressor (MetJ) system. FEBS Letters, 348 (1). pp. 41-45. ISSN 0014-5793 (doi:10.1016/0014-5793(94)00579-6)

Full text not currently available from Enlighten.

Publisher's URL: http://dx.doi.org/10.1016/0014-5793(94)00579-6

Abstract

Calorimetric measurements of binding of a specific DNA fragment and S-adenosyl methionine (SAM) co-repressor molecules to the E. Coli methionine repressor (MetJ) show significant differences in the energetics of binary and ternary protein-DNA complexes. Formation of the MetJ: SAM: DNA ternary complex is significantly more exothermic (ΔH ⋍ −99 kJ•mol−1) than either MetJ:DNA or MetJ:SAM binary complexes alone (ΔH ⋍ −10 kJ•mol−1 each). The protein is also significantly more stable to unfolding (ΔTm ⋍ 5.4°C) when bound to DNA. These observations suggest that binding of SAM to the protein-DNA complex leads to a significant reduction in dynamic flexibility of the ternary complex, with considerable entropy-enthalpy compensation, not necessarily involving any overall conformational change.

Item Type:Article
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Cooper, Prof Alan
Authors: Cooper, A., Mcalpine, A., and Stockley, P. G.
Subjects:Q Science > QH Natural history > QH345 Biochemistry
College/School:College of Science and Engineering > School of Chemistry
Journal Name:FEBS Letters
Publisher:Elsevier BV
ISSN:0014-5793
ISSN (Online):1873-3468
Published Online:19 October 2001

University Staff: Request a correction | Enlighten Editors: Update this record