Fig. 3

The SAA method defining the N-terminal, middle, and C-terminal regions based on the sequence length L. If L is no less than 4d _N  + 20 + d _c , the N-terminal of each part d _N is represented 25 residues in the start region of sequence. The middle regions have more than 20 residues, and the length of the C-terminal regions d _c is set as 10 residues (a). If L is between 4d _N  + d _c and 4d _N  + 20 + d _c , the N-terminal of each part d _N is represented by 20 residues in the start part. Thus, the middle part has less than 20 residues (b). For short sequence, if L is no less than 4d _N  + d _c , the N-terminal part is not divided and the lengths of the middle and N-terminal regions are set as (L-d _c )/2 (c)