Predicted secondary structure of glycogen phosphorylase from Escherichia coli as deduced using Chou-Fasman analysis

Secondary structure of glycogen phosphorylase from Escherichia coli has been deduced using Chou-Fasman analysis. Out of 809 amino acid residues, 244 residues showed formation of alpha-helix (30%), 218 residues beta-pleated sheet (27%) and 192 residues (24%) showed formation of reverse beta turn, distributed all over the sequence. There are total 27 alpha-helix and 31 beta-pleated sheets distributed all over the molecule. A structure consisting of three consecutive strands of beta-pleated sheets and two joining alpha-helix is predicted for the stretch of the primary sequence from residues 325 to 372, thus showing the presence of a Rossman fold super secondary structure. There is a tyrosine at position 350 in the super secondary structure, in the area to contain a reverse beta turn. Several amino acids pairs are present in the sequence having Rossman fold super secondary structure.