Predicted three-dimensional positioning of ten functionally important essential amino acids in AChE1a (white) and AChE1b (grey) from Lepeophtheirus salmonis and the AChE template (PDB-ID 1qo9) from Drosophila melanogaster (blue) was used. SWISS MODEL in the automated mode  (http://swissmodel.expasy.org/) was used for modelling. The numbering is from T. californica. The catalytic triad amino acids S200, E327 and H440 were predicted to be in almost exactly the same positions in all proteins. The same goes for the important acyl pocket residues W233, F290, F331, the choline binding site W84 and the oxyanion hole residues G118, G119 and A201.