of the four amino acid sequences determined , two sequences surrounding phosphorylated amino acids , -lys-tyr-leu-ala-ser ( p ) 16-ala- and -arg-phe-ser ( p ) 115-trp-gly- , have both sides of each phosphoserine residue occupied by hydrophobic amino acids , and a basic amino acid , arginine or lysine , is located at the position 2 or 4 residues amino-terminal to the phosphoserine residue .
C0301714
basic amino acid
C0003765
arginine