The histidine phosphocarrier protein, HPr, binds to the highly thermostable regulator of sigma D protein, Rsd, and its isolated helical fragments.
Neira JL, Hornos F, Cozza C, Cámara-Artigas A, Abián O, Velázquez-Campoy A. Arch Biochem Biophys. 2018 Feb 1; 639:26-37. Epub 2017 Dec 27.