Structure of the Ets-1 pointed domain and mitogen-activated protein kinase phosphorylation site

Structure of the Ets-1 pointed domain and mitogen-activated protein kinase phosphorylation site

^*Department of Biochemistry and Molecular Biology and Department of Chemistry, University of British Columbia, Vancouver, British Columbia, Canada, V6T 1Z3; and ^†Huntsman Cancer Institute, Department of Oncological Sciences, University of Utah School of Medicine, Salt Lake City, UT 84312

Communicated by Peter S. Kim, Massachusetts Institute of Technology, Cambridge, MA (received for review July 16, 1998)

Abstract

The Pointed (PNT) domain and an adjacent mitogen-activated protein (MAP) kinase phosphorylation site are defined by sequence conservation among a subset of ets transcription factors and are implicated in two regulatory strategies, protein interactions and posttranslational modifications, respectively. By using NMR, we have determined the structure of a 110-residue fragment of murine Ets-1 that includes the PNT domain and MAP kinase site. The Ets-1 PNT domain forms a monomeric five-helix bundle. The architecture is distinct from that of any known DNA- or protein-binding module, including the helix-loop-helix fold proposed for the PNT domain of the ets protein TEL. The MAP kinase site is in a highly flexible region of both the unphosphorylated and phosphorylated forms of the Ets-1 fragment. Phosphorylation alters neither the structure nor monomeric state of the PNT domain. These results suggest that the Ets-1 PNT domain functions in heterotypic protein interactions and support the possibility that target recognition is coupled to structuring of the MAP kinase site.

Footnotes

↵ ‡ To whom reprint requests should be addressed at: Department of Biochemistry, 2146 Health Sciences Mall, University of British Columbia, Vancouver, BC, Canada, V6T 1Z3. e-mail: mcintosh{at}otter.biochem.ubc.ca.
Data deposition: The coordinates, restraints, and chemical shifts for Ets-1^(29–138) reported in this paper have been deposited in the Protein Data Bank, Biology Department, Brookhaven National Laboratory, Upton, NY 11973 (PDB ID codes 1bqv and r1bqvmr).
ABBREVIATIONS:

PNT,

Pointed;

HSQC,

heteronuclear single quantum correlation;

MAP,

mitogen-activated protein;

NOESY,

nuclear Overhauser effect spectroscopy