Previous Article | Next Article ![]()
Mol. Cell. Biol., May 1997, 2876-2887, Vol 17, No. 5
AG West, P Shore and AD Sharrocks
The serum response factor (SRF) and myocyte enhancer factor 2A (MEF2A)
represent two human members of the MADS-box transcription factor family.
Each protein has a distinct biological function which is reflected by the
distinct specificities of the proteins for coregulatory protein partners
and DNA-binding sites. In this study, we have investigated the mechanism of
DNA binding utilized by these two related transcription factors. Although
SRF and MEF2A belong to the same family and contain related DNA-binding
domains, their DNA-binding mechanisms differ in several key aspects. In
contrast to the dramatic DNA bending induced by SRF, MEF2A induces minimal
DNA distortion. A combination of loss- and gain-of-function mutagenesis
identified a single amino acid residue located at the N terminus of the
recognition helices as the critical mediator of this differential DNA
bending. This residue is also involved in determining DNA-binding
specificity, thus indicating a link between DNA bending and DNA-binding
specificity determination. Furthermore, different basic residues within the
putative recognition alpha-helices are critical for DNA binding, and the
role of the C-terminal extensions to the MADS box in dimerization between
SRF and MEF2A also differs. These important differences in the molecular
interactions of SRF and MEF2A are likely to contribute to their differing
roles in the regulation of specific gene transcription.
Copyright © 1997, American Society for Microbiology
DNA binding by MADS-box transcription factors: a molecular mechanism for differential DNA bending
Department of Biochemistry and Genetics, Medical School, University of Newcastle upon Tyne, United Kingdom.
This article has been cited by other articles:
Copyright © 2009 by the American Society for Microbiology. For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»