D-galactoside/L-rhamnose binding SUEL lectin domain (IPR000922)

Short name: Lectin_gal-bd_dom

Overlapping homologous superfamilies


Domain relationships



The D-galactoside binding lectin purified from sea urchin (Anthocidaris crassispina) eggs exists as a disulphide-linked homodimer of two subunits; the dimeric form is essential for hemagglutination activity [PMID: 2001368]. The sea urchin egg lectin (SUEL) forms a new class of lectins. Although SUEL was first isolated as a D-galactoside binding lectin, it was latter shown that it bind to L-rhamnose preferentially [PMID: 2001368, PMID: 10564781]. L-rhamnose and D-galactose share the same hydroxyl group orientation at C2 and C4 of the pyranose ring structure.

A cysteine-rich domain homologous to the SUEL protein has been identified in the following proteins [PMID: 9261169, PMID: 9668106, PMID: 9920906]:

  • Plant beta-galactosidases (EC: (lactases).
  • Mammalian latrophilin, the calcium independent receptor of alpha-latrotoxin (CIRL). The galactose-binding lectin domain is not required for alpha-latratoxin binding [PMID: 9920906].
  • Human lectomedin-1.
  • Rhamnose-binding lectin (SAL) from catfish (Silurus asotus, Namazu) eggs. This protein is composed of three tandem repeat domains homologous to the SUEL lectin domain. All cysteine positions of each domain are completely conserved [PMID: 10564781].
  • The hypothetical B0457.1, F32A7.3A and F32A7.3B proteins from Caenorhabditis elegans.
  • The human KIAA0821 protein.

GO terms

Biological Process

No terms assigned in this category.

Molecular Function

GO:0030246 carbohydrate binding

Cellular Component

No terms assigned in this category.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.
PROSITE profiles