Solution conformation of an essential region of the p53 transactivation domain.
BACKGROUND
The peptide segment surrounding residues Leu22 and Trp23 of the p53 transactivation domain plays a critical role in the transactivation activity of p53. This region binds basal transcriptional components such as the TATA-box binding protein associated factors TAFII40 and TAFII60 as well as the mdm-2 and adenovirus type 5 E1B 55 kDa oncoproteins.


RESULTS
The structure of residues 14-28 of p53 was studied by nuclear magnetic resonance spectroscopy and found to prefer a two-beta-turn structure stabilized by a hydrophobic cluster consisting of residues known to be important for transactivation and binding to p53-binding proteins. A peptide segment in which Leu22 and Trp23 were replaced by Gln and Ser displays a random structure.


CONCLUSIONS
This structural propensity observed in the wild-type p53 peptide is important for understanding the mechanism of transcriptional activation, because very few structural data are available on transactivation domains to date. These results should aid in the design of therapeutics that could competitively inhibit binding of p53 to the oncogene product mdm-2.
Botuyan
M V
MV
Division of Immunology, Beckman Research Institute of the City of Hope, Duarte, CA 91010, USA.
Momand
J
J
Chen
Y
Y
D000595:Amino Acid Sequence; D001665:Binding Sites; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry; D011487:Protein Conformation; D017434:Protein Structure, Tertiary; D012996:Solutions; D013696:Temperature; D015534:Trans-Activators / Q000737:chemistry*; D016159:Tumor Suppressor Protein p53 / Q000737:chemistry*
D010446:Peptide Fragments; D012996:Solutions; D015534:Trans-Activators; D016159:Tumor Suppressor Protein p53