Fig. 1

Structural and phylogenic comparison of zebrafish TM-a and TM-b. The amino acid sequences of TMs from the indicated species were analyzed and compared for functional domains and evolutionary trace. a The domain structures of zebrafish TM-a and TM-b were predicted with on-line software (SMART: http://smart.embl-heidelberg.de/) and compared with human TM. The depicted functional domains include: signal peptide (black oblong), c-type lectin domain (white rhomboid), EGF-like domain (white inverted triangles), an O-glycosylation site-rich region (dotted-line) and transmembrane domain (white oblong). b Clustering algorithm shows the evolutionary relationships of TMs among the compared species (ClustalW, SDSC Biology WorkBench http://workbench.sdsc.edu. c The similarity and percent of identity among the TM primary structures of the selected mammalian and aquatic species were compared. d The peptide sequences of TM EGF-like domains from the indicated species were aligned. The shaded letters indicate the amino acids that are identical among compared species. The residues indicated by asterisks are the cysteine residues participating in disulfide bonds and conserved during evolution. e The 3D structures of zTM-a (aa299 – aa410) and zTM-b (aa339 – aa452) were modeled with the on-line software SWISS-MODEL using the partial 3D structure of human TM (aa364 – aa480) available in the database as template. The compared peptide sequences include: Zebrafish TM-a (MF 694564); Zebrafish TM-b (MF 694565); Human TM (NP_000352); Chimpanzee TM (XP_003829427); Rat TM (NP_113959); Rabbit TM (NP_001075613); Xenopus TM (XP_002936969); Fugu TM (XP_003971425)