The comparison result of a naturally occurring protein pair 1RIN/180 and 2CNA/237 by SAMO. The subfigures (a) and (c) are backbone of proteins 1RIN and 2CNA respectively. The subfigure (c) illustrates the aligned result after the optimal superimposing by different colors. The red chain is 2CNA and the blue chain is 1RIN. The two termini of the two structures are indicated by labeling their residue names respectively. Notice that the termini of the blue chain (1RIN) are aligned to the middle of the red chain (2CNA) and vice versa.