A concanavalin A-like lectin domain in the CHS1/LYST protein, shared by members of the BEACH family

CHS1/LYST, the causative protein of the Chediak–Higashi syndrome (CHS), belongs to the BEACH (named after BEige And Chediak–Higashi) family, which includes various large proteins sharing the same C-terminal domain architecture [a PH (Pleckstrin homology)–BEACH domain followed by WD repeats). Members of the BEACH family are generally defined as vesicle-trafficking regulatory proteins, but their functions remain to be determined at the molecular level. Here, using a panel of sensitive methods of sequence analysis, we show that the N-terminal regions of BEACH proteins contain an as yet not described domain, which shares striking similarities with clostridial neurotoxins and defines a novel family within the concanavalin A (ConA)-like lectin superfamily. These results suggest that the BEACH ConA-like lectin domain could be involved in oligosaccharide binding associated with protein traffic and sorting along the secretory pathway, especially in relation with components of the vesicle fusion machinery. Contact: isabelle.callebaut@impmc.jussieu.fr Supplementary information: Supplementary data are available at Bioinformatics online.