INCREASED SALT CONCENTRATION REVERSIBLY DESTABILIZES P53 QUATERNARY STRUCTURE AND SEQUENCE-SPECIFIC DNA-BINDING

Growth suppression by p53 correlates with sequence-specific DNA bindin g and is determined by tertiary and quaternary protein structures. Exp osure to 300 mM NaCl did not affect p53 tertiary structure, but dissoc iated high-molecular-mass complexes with concomitant loss of specific DNA binding. Both effects were reversible. We conclude that high salt can reversibly destabilize the quaternary structure of p53 that is mos t efficient for sequence-specific DNA binding.