{PDOC50228} {PS50228; SUEL_LECTIN} {BEGIN} *********************************** * SUEL-type lectin domain profile * *********************************** Lectins bind to specific carbohydrate residues of glycoproteins and glycolipids present at the cell surface. This allow them to agglutinate a variety of cellular types. On the basis of sequence similarity and common characteristics such as sugar binding specificity, conserved carbohydrate recognition domains, and ion requirement the different lectins can be grouped in different categories, like C-type, I-type, galectins, pentraxins and P-type lectin. The sea urchin (Anthocidaris crassispina) egg lectin (SUEL) forms a new class of lectins. Altough SUEL was first isolated as a D-galactoside binding lectin it was latter shown that it bind to L-rhamnose preferentially [1,2]. L- rhamnose and D-galactose share the same hydroxyl group orientation at C2 and C4 of the pyranose ring structure. SUEL is a lectin that exist as a disulfide linked homodimer. The dimeric form is essential for hemagglutination activity but the monomeric form retains carbohydrate binding capacity [1]. Based on primary structure analysis, a cysteine-rich domain homologous to the SUEL protein has been identified in the following proteins [3,4,5]: - Plant beta-galactosidases (EC 3.2.1.23) (lactases). They constitute a widespread family of enzymes characterized by their ability to hydrolyse terminal, non-reducing beta D-galactosyl residues from beta-D-galactosides. - Mammalian latrophilin, the calcium independent receptor of alpha- latrotoxin (CIRL). It belongs to the secretin family of G-protein coupled receptors. The lectin domain is not required for alpha-latratoxin binding [5]. - Human lectomedin-1. - Rhamnose-binding lectin (SAL) from catfish (Parasilurus asotus) 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 [2]. - Caenorhabditis elegans hypothetical proteins B0457.1, F32A7.3A and F32A7.3B. - Human hypothetical protein KIAA0821. -Sequences known to belong to this class detected by the profile: ALL. -Other sequence(s) detected in Swiss-Prot: NONE. -Last update: December 2001 / First entry. [ 1] Ozeki Y., Matsui T., Suzuki M., Titani K. "Amino acid sequence and molecular characterization of a D-galactoside-specific lectin purified from sea urchin (Anthocidaris crassispina) eggs." Biochemistry 30:2391-2394(1991). PubMed=2001368 [ 2] Hosono M., Ishikawa K., Mineki R., Murayama K., Numata C., Ogawa Y., Takayanagi Y., Nitta K. "Tandem repeat structure of rhamnose-binding lectin from catfish (Silurus asotus) eggs." Biochim. Biophys. Acta 1472:668-675(1999). PubMed=10564781 [ 3] Lelianova V.G., Davletov B.A., Sterling A., Rahman M.A., Grishin E.V., Totty N.F., Ushkaryov Y.A. "Alpha-latrotoxin receptor, latrophilin, is a novel member of the secretin family of G protein-coupled receptors." J. Biol. Chem. 272:21504-21508(1997). PubMed=9261169 [ 4] Tateno H., Saneyoshi A., Ogawa T., Muramoto K., Kamiya H., Saneyoshi M. "Isolation and characterization of rhamnose-binding lectins from eggs of steelhead trout (Oncorhynchus mykiss) homologous to low density lipoprotein receptor superfamily." J. Biol. Chem. 273:19190-19197(1998). PubMed=9668106 [ 5] Krasnoperov V., Bittner M.A., Holz R.W., Chepurny O., Petrenko A.G. "Structural requirements for alpha-latrotoxin binding and alpha-latrotoxin-stimulated secretion. A study with calcium-independent receptor of alpha-latrotoxin (CIRL) deletion mutants." J. Biol. Chem. 274:3590-3596(1999). PubMed=9920906 -------------------------------------------------------------------------------- PROSITE is copyrighted by the SIB Swiss Institute of Bioinformatics and distributed under the Creative Commons Attribution-NonCommercial-NoDerivatives (CC BY-NC-ND 4.0) License, see https://prosite.expasy.org/prosite_license.html -------------------------------------------------------------------------------- {END}