Fig. 3

Schematic representations of the deduced structure and conserved consensus motifs of the fish and human ANGPTLs. The signal peptide region (SP, small open box), the coiled-coil domain (CCD, helix) and the highly conserved fibrinogen-related domain (FReD, long open box) are annotated and to facilitate visualization protein structures were aligned using the FReD motif. The four conserved cysteine residues within the FReD motif potentially involved in the establishment of two intramolecular disulphide bonds are represented and indicated by “S-S” in the Angptl1 protein structure and their positions were obtained from Uniprot annotation. Other vertebrate conserved cysteine residues are represented by “C” and predicted N-glycosylation (N-x-T/S) motifs are annotated with “N”. Across fish, the amino acid residues that regulate the activity of the human ANGPTL4 (His⁴⁶, Gln⁵⁰ and Gln⁵³) [66] are also conserved. The figure is not drawn to scale and the percent of amino acid sequence similarity between the fish and the human orthologues is indicated with the exception of Angptl9 that considers the similarity across fish. The ANGPTL 8 is not represented, as it is only present in mammals. The complete alignments of the human and fish Angptl proteins are available in Additional file 4: Figure S3a–d. * The sequence similarity of the coelacanth duplicates was not considered, as their sequence was highly divergent