MOLECULAR MODELING OF TWO HEXAPEPTIDE REPEAT MOTIFS OF HMW GLUTENIN SUBUNITS

The three-dimensional structures of two hexapeptide repeat motifs (PGQGQQ and SGQGQQ, in one letter code) in the repetitive central domain of HMW glutenin subunits are investigated by using the multicanonical simulation procedure. Ramachandran plots were prepared and analyzed to predict the relative occurrence probabilities of β-turn and γ-turn structures and helical state. Structural predictions of PGQGQQ repeat motif indicated the presence of high level of β-turns and considerable level of γ-turns. Simulations of the repeat motifs in the repetitive central domain of HMW glutenin subunits indicated that these structures take important part in the three-dimensional structures of repeat motifs.