FIG. 3.

NAD⁺ binding, affecting p53 conformation and specifically inhibiting p53 tetramer DNA binding in vitro. (A, left) Equal amounts of p53 and L344A were incubated with ³²P-NAD⁺. (Right) Bound ³²P-NAD⁺. Signal strength is indicated below each spot; signal strength for anti-p53 is arbitrarily 100%. (B) [³⁵S]methionine-labeled proteins were incubated with NAD⁺ or NADH and then digested with trypsin (tryp). The percentage of undigested p53 (arrow) is indicated below each lane. (C) NAD⁺ was added with ³²P-hdm2 (top) or ³²P-p21 (bottom) to p53 tetramers or dimers. DNA-bound proteins are tetramers (4×), single L344A dimers (2×), or pairs of L344A dimers (2-2×).