Fig. 3.

Protein sequence conservation of choanoflagellate semaphorins and plexins. (A) Sequence conservation plot for Craspedida Sema-FN1. The highest conserved parts are the PSI domain and the SEA domain, whereas the intracellular part exhibits lowest sequence conservation, except for the CMC motif. The y axis represents similarity score calculated by plotcon algorithm, based on protein alignments (window size of 75 aa). Note that some protein domains stretched out according to alignments and are not to scale. SP, signal peptide; FN III, fibronectin type III domain; TM, transmembrane domain. CMC, conserved motif near C-terminus. (B) Conservation plot of Sema-FN1 sequences of Acanthoecida shows high sequence conservation of the Reeler and the Sema domains, but low conservation of the S/T-rich domain. (C) Sequence conservation plot for choanoflagellate Plexin-1. The highest conservation is in the intracellular Ras-GAP domain, which is interrupted by the insert of a less conserved RBD domain. JM, juxtamembrane helix. See also fig. 1 for domain names.