Lectin activity of the nucleocytoplasmic EUL protein from Arabidopsis thaliana.

The Euonymus lectin (EUL) domain was recognized as the structural motif for a novel class of putative carbohydrate binding proteins. Confocal microscopy demonstrated that the lectin from Euonymus europaeus (EEA) as well as the EUL protein from Arabidopsis thaliana (ArathEULS3) are located in the nucleocytoplasmic compartment of the plant cell. ArathEULS3 as well as its EUL domain were successfully expressed in Pichia pastoris and purified. The EUL domain from Arabidopsis interacts with glycan structures containing Lewis Y, Lewis X and lactosamine, indicating that it can be considered a true lectin domain. Despite the high sequence identity between the EUL domains in EEA and ArathEULS3, both domains recognize different carbohydrate structures.