Structure based sequence comparison of ecRBP and tteRBP. Comparison of sequence identities (black squares) and similarities (open squares) of tteRBP and ecRBP by scoring the number of identical residues in 3 Å concentric shells centered on the mid-point of the bound-ribose. The residues in the last two bins were combined due to the few members in the largest bin. In the primary complementary surface (first shell, 9 Å), the two sequences are identical; at the furthest distance the two sequences are 34% identical and 74% similar. Solid lines are a linear fit of the data to the observations.