Homologous vs. analogous proteins

Table 1 shows which proteins were classified as functionally similar (i.e., type or ), and on all plots described above, a line is drawn to separate type similarities (i.e., those having ) from others. Within all plots, type and similarities are labelled as `x', whereas type similarities are labelled `o'. Table 5 shows the degree of property conservation for the three protein structural pairs (of type , and ) shown in Figure 11. Table 6 shows a general summary of the range of structural features for all the types of similarities. For pairs of 3D structures having (i.e., the range of for type similarities), no difference can be seen in the Table or any of the plots between those structures with functional similarity and those without. Flores et al. (1993) found little difference in the conservation of accessibility, Ooi numbers, secondary structure and angle between homologous and analogous pairs of 3D structures. The results presented here agree with their findings. It would seem that even with the restriction of functional similarity, protein structures (and sequences) can vary significantly.