We now look for two kinds of residues. First the other totally conserved ones, as they
might be involved in supporting the common aspects of the activity of the two
subfamilies. Here the conserved glycine might be needed for mobility, the conserved
proline for maintaining a certain structure element (e.g. a turn), and the conserved
glutamine might provide some hydrogen bonds for the binding. I skip the leucines
as they cannot do anything special.
And secondly, we will need to find residues that are at the same position conserved in each of the two families, but different between the two families, and additionally they should be a bit suspicious...
I find a S/T, a T/S, a G/S, an A/G, and an I/G. The S/T and T/S might form a similar hydrogen bond in a slightly different way. The G/S might provide slightly different turns, and the A/G and I/G might provide mobility differences. there are also some combinations like I/L, but I and L are both useless...