Electrostatic determinants of stability in parallel 3-stranded coiled coils

Abstract

The optimal positioning of salt-bridging interactions in a parallel α-helical homotrimeric coiled coil has been explored in a metal ion-assembled polypeptide trimer of 60 residues; arginine–glutamate pairs are more stabilizing than the corresponding lysine–glutamate pairs, and optimal stabilization is obtained with positively charged arginine residues at the c positions of the α-helical heptad and negatively charged glutamate residues at the e positions.