Fig. 9.

Changes in conservation patterns and functional motifs of arrestins. Conservation of alignment positions of the individual orthology groups is shown. The conservation was calculated according to the Method of Karlin [110] using AACon [111] for each orthology group separately. Sequences with a coverage < 90% as well as all lamprey sequences were excluded. Functional motifs characterized in one or several paralogs were projected onto the individual alignments solely based on sequence homology. Putative loss (pentagon) and gain (circle) events based on conservation of the respective motifs were projected onto a simplified arrestin gene tree. The order of motif gain and loss on the respective branch was chosen arbitrarily. Positions were not marked if they did not conserve the amino acid known to be part of the motif in that orthology group in a majority of representatives. Some positions are marked although their conservation is restricted to a phylogenetic group as indicated by their lower conservation score (e.g. oligomerization is specific for Sarcopterygii SAG). The secondary structure based on the crystal structure of 1G4R (Fig. 1) is mapped onto the alignment of ARRB1. Note that only a selection of known motifs are shown