PAM250 is one of a family of alignment scoring matrices introduced by Margaret Dayhoff in 1978.
A C D E F G H I K L M N P Q R S T V W Y A 2 -2 0 0 -3 1 -1 -1 -1 -2 -1 0 1 0 -2 1 1 0 -6 -3 C -2 12 -5 -5 -4 -3 -3 -2 -5 -6 -5 -4 -3 -5 -4 0 -2 -2 -8 0 D 0 -5 4 3 -6 1 1 -2 0 -4 -3 2 -1 2 -1 0 0 -2 -7 -4 E 0 -5 3 4 -5 0 1 -2 0 -3 -2 1 -1 2 -1 0 0 -2 -7 -4 F -3 -4 -6 -5 9 -5 -2 1 -5 2 0 -3 -5 -5 -4 -3 -3 -1 0 7 G 1 -3 1 0 -5 5 -2 -3 -2 -4 -3 0 0 -1 -3 1 0 -1 -7 -5 H -1 -3 1 1 -2 -2 6 -2 0 -2 -2 2 0 3 2 -1 -1 -2 -3 0 I -1 -2 -2 -2 1 -3 -2 5 -2 2 2 -2 -2 -2 -2 -1 0 4 -5 -1 K -1 -5 0 0 -5 -2 0 -2 5 -3 0 1 -1 1 3 0 0 -2 -3 -4 L -2 -6 -4 -3 2 -4 -2 2 -3 6 4 -3 -3 -2 -3 -3 -2 2 -2 -1 M -1 -5 -3 -2 0 -3 -2 2 0 4 6 -2 -2 -1 0 -2 -1 2 -4 -2 N 0 -4 2 1 -3 0 2 -2 1 -3 -2 2 0 1 0 1 0 -2 -4 -2 P 1 -3 -1 -1 -5 0 0 -2 -1 -3 -2 0 6 0 0 1 0 -1 -6 -5 Q 0 -5 2 2 -5 -1 3 -2 1 -2 -1 1 0 4 1 -1 -1 -2 -5 -4 R -2 -4 -1 -1 -4 -3 2 -2 3 -3 0 0 0 1 6 0 -1 -2 2 -4 S 1 0 0 0 -3 1 -1 -1 0 -3 -2 1 1 -1 0 2 1 -1 -2 -3 T 1 -2 0 0 -3 0 -1 0 0 -2 -1 0 0 -1 -1 1 3 0 -5 -3 V 0 -2 -2 -2 -1 -1 -2 4 -2 2 2 -2 -1 -2 -2 -1 0 4 -6 -2 W -6 -8 -7 -7 0 -7 -3 -5 -3 -2 -4 -4 -6 -5 2 -2 -5 -6 17 0 Y -3 0 -4 -4 7 -5 0 -1 -4 -1 -2 -2 -5 -4 -4 -3 -3 -2 0 10
