Assignment of H-1(N), N-15, C-13(alpha), (CO)-C-13 and C-13(beta) resonances in a 67 kDa p53 dimer using 4D-TROSY NMR spectroscopy

The p53 tumor suppressor is a transcription factor that plays a crucial rol e in the activation of genes in response to DNA damage. As a first step tow ards detailed structural studies of the molecule aimed at understanding its regulation, we have used 4D-TROSY triple resonance NMR spectroscopy to obt ain nearly complete H-1(N), N-15, C-13(alpha), (CO)-C-13 and C-13(beta) res onance assignments of a dimeric form of the protein comprising DNA-binding and oligomerization domains (67 kDa). A simple comparison of 4D spectra rec orded on p53 molecules consisting of DNA-binding and oligomerization domain s with and without the regulatory domain establishes that both constructs h ave essentially identical chemical shifts. Although the affinity of p53 for target DNA is decreased in constructs containing the regulatory domain, th e chemical shift results reported here suggest that this decrease is not du e to specific domain interactions involving the regulatory portion of the m olecule, or alternatively, that such interactions require the presence of D NA.