The effect of CtBP1 binding on the structure of the C-terminal region of adenovirus 12 early region 1A
- Cancer Research UK Institute for Cancer Studies, University of Birmingham, Birmingham B15 2TT (United Kingdom)
Adenovirus early region 1A (AdE1A) binds to the C-terminal binding protein 1 (CtBP1) primarily through a highly conserved PXDLS motif located close to its C-terminus. Purified synthetic peptides equivalent to this region of AdE1A have been shown to form a series of {beta}-turns. In this present study the effect of CtBP1 binding on the conformation of C-terminal region of Ad12E1A has been investigated. Using one- and two-dimensional {sup 1}H NMR spectroscopy, the conformation of 20-residue peptides equivalent to amino acids I{sup 241}-V{sup 260} and E{sup 247}-N{sup 266} of Ad12E1A were examined in the absence of CtBP1. Whilst the latter peptide forms a series of {beta}-turns in its C-terminal half as reported previously, the former peptide is {alpha}-helical over the region D{sup 243}-Q{sup 253}. Upon interaction with CtBP1 the conformation of the backbone in the region {sup 255}PVDLCVK{sup 261} of the Ad12E1A E{sup 247}-N{sup 266} peptide reorganises from a predominately {beta}-turn to an {alpha}-helical conformation. This structural isomerisation is characterised by a shift upfield of 0.318 ppm for the {delta}-CH{sub 3} proton resonance of V{sup 256}. 2-D NOESY experiments showed new signals in the amide-{alpha} region which correlate to transferred NOEs from the protein to the peptide residues E{sup 251}, V{sup 256} and K{sup 261}. In further analyses the contribution of individual amino acids within the sequence {sup 254}VPVDLS{sup 259} was assessed for their importance in determining structure and consequently affinity of the peptide for CtBP. It has been concluded that Ad12E1A residues {sup 255}P-V{sup 260} serve initially as a recognition site for CtBP and then as an anchor through a {beta}-turns {sup {yields}} {alpha}-helix conformational rearrangement. In addition it has been predicted that regions N-terminal to the PXDLS motif in AdE1As from different virus serotypes and from mammalian proteins form {alpha}-helices.
- OSTI ID:
- 20977037
- Journal Information:
- Virology, Vol. 363, Issue 2; Other Information: DOI: 10.1016/j.virol.2007.01.039; PII: S0042-6822(07)00047-5; Copyright (c) 2007 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); ISSN 0042-6822
- Country of Publication:
- United States
- Language:
- English
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