Aquifex aeolicus FlgM protein exhibits a temperature-dependent disordered nature.

Studies on the nature and function of intrinsically disordered proteins (IDP) over the past 10 years have demonstrated the importance of IDPs in normal cellular function. Although many proteins predicted to be IDPs have been experimentally characterized on an individual basis, the conservation of disorder between homologous proteins from different organisms has not been fully studied. We now demonstrate that the FlgM protein from the thermophile Aquifex aeolicus exhibits a more ordered conformation at 20 degrees C than the previously characterized FlgM protein from Salmonella typhimurium.

Conformational detection of p53's oligomeric state by FlAsH Fluorescence.

The p53 tumor suppressor protein is a critical checkpoint in prevention of tumor formation, and the function of p53 is dependent on proper formation of the active tetramer. In vitro studies have shown that p53 binds DNA most efficiently as a tetramer, though inactive p53 is predicted to be monomeric in vivo. We demonstrate that FlAsH binding can be used to distinguish between oligomeric states of p53, providing a potential tool to explore p53 oligomerization in vivo.