1r36
From Proteopedia
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NMR-based structure of autoinhibited murine Ets-1 deltaN301
Overview
The transcription factor Ets-1 is regulated by the allosteric coupling of, DNA binding with the unfolding of an alpha-helix (HI-1) within an, autoinhibitory module. To understand the structural and dynamic basis for, this autoinhibition, we have used NMR spectroscopy to characterize, Ets-1DeltaN301, a partially inhibited fragment of Ets-1. The NMR-derived, Ets-1DeltaN301 structure reveals that the autoinhibitory module is formed, predominantly by the hydrophobic packing of helices from the N-terminal, (HI-1, HI-2) and C-terminal (H4, H5) inhibitory sequences, along with H1, of the intervening DNA binding ETS domain. The intramolecular interactions, made by HI-1 in Ets-1DeltaN301 are similar to the intermolecular contacts, observed in the crystal structure of an Ets-1DeltaN300 dimer, confirming, that the latter represents a domain-swapped species. (15)N relaxation, studies demonstrate that the backbone of the N-terminal inhibitory, sequence is mobile on the nanosecond-picosecond and, millisecond-microsecond time scales. Furthermore, hydrogen exchange, measurements reveal that amide protons in helices HI-1 and HI-2 exchange, with water at rates only approximately 15- and approximately 75-fold, slower, respectively, than predicted for an unfolded polypeptide. These, findings indicate that inhibitory helices are only marginally stable even, in the absence of DNA. The energetic coupling of DNA binding with the, facile unfolding of the labile HI-1 provides a mechanism for modulating, Ets-1 DNA binding activity via protein partnerships, post-translational, modifications, or mutations. Ets-1 autoinhibition illustrates how, conformational equilibria within structural domains can regulate, macromolecular interactions.
About this Structure
1R36 is a Single protein structure of sequence from Mus musculus. This structure superseeds the now removed PDB entries 1ETC and 1ETD. Full crystallographic information is available from OCA.
Reference
The structural and dynamic basis of Ets-1 DNA binding autoinhibition., Lee GM, Donaldson LW, Pufall MA, Kang HS, Pot I, Graves BJ, McIntosh LP, J Biol Chem. 2005 Feb 25;280(8):7088-99. Epub 2004 Dec 9. PMID:15591056
Page seeded by OCA on Wed Nov 21 01:14:13 2007
