The sequence of Daphnia pulex neurotrophin. A. Predicted amino acid sequence of Dappu-NT, the Daphnia pulex neurotrophin. The signal peptide is underlined and the putative propeptide cleavage site is marked by an arrow head. Conserved Cysteines for the characteristic Cys knot are in white against a black background. B. Alignment of Dappu-NT C-terminus to other neurotrophin C-termini. Identical residues are in white over a grey background. The 5 Cys (white on black background) of the neurotrophin Cys-knot are conserved. Most residues from the vertebrate neurotrophin consensus motif " [GSRE]-C- [KRL]-G- [LIVT]- [DE]-x(3)- [YW]-x-S-x-C" are also conserved (underlined). Hs: Homo sapiens, Bf: Branchiostoma floridae, Sp: Strongylocentrotus purpuratus, Sk: Saccoglossus kowalevskii.