Alignment of three sequences by dynamic programming For three protein sequences each 300 amino acids in length and excluding gaps, the number of comparisons to be made by dynamic programming is equal to 3003=2.7 X 107, whereas only 3002=9 X104 is required for two sequences of this length (The number of steps and memory required for N M-amino-acid sequences: Mv Carrillo and Lipman(1988) found a way(the sum of pairs, sP method, the msa program)to reduce the number of comparisons that must be made without compromising the attempt to find an optimal alignmentAlignment of three sequences by dynamic programming • For three protein sequences each 300 amino acids in length and excluding gaps, the number of comparisons to be made by dynamic programming is equal to 3003 = 2.7 ×107 , whereas only 3002 = 9 ×104 is required for two sequences of this length. (The number of steps and memory required for N M-amino-acid sequences: MN) • Carrillo and Lipman (1988) found a way (the sum of pairs, SP method, the MSA program) to reduce the number of comparisons that must be made without compromising the attempt to find an optimal alignment