{PDOC00279} {PS51304; GALECTIN} {BEGIN} ******************************************************** * Galactoside-binding lectin (galectin) domain profile * ******************************************************** Galectins (also known as galaptins or S-lectin) are a family of proteins defined by having at least one characteristic carbohydrate recognition domain (CRD) with an affinity for beta-galactosides and sharing certain sequence elements. Members of the galectins family are found in mammals, birds, amphibians, fish, nematodes, sponges, and some fungi. Galectins are known to carry out intra- and extracellular functions through glycoconjugate-mediated recogntion. From the cytosol they may be secreted by non-classical pathways, but they may also be targeted to the nucleus or specific sub-cytosolic sites. Within the same peptide chain some galectins have a CRD with only a few additional amino acids, whereas others have two CRDs joined by a link peptide, and one (galectin-3) has one CRD joined to a different type of domain [1-3]. The galectin carbohydrate recognition domain (CRD) is a beta-sandwich of about 135 amino acid (see ). The two sheets are slightly bent with 6 strands forming the concave side and 5 strands forming the convex side. The concave side forms a groove in which carbohydrate is bound, and which is long enough to hold about a linear tetrasaccharide [1-5]. A number of proteins are known to belong to this family: - Galectin-3 (also known as MAC-2 antigen; CBP-35 or IgE-binding protein), a 35 Kd lectin which binds immunoglobulin E and which is composed of two domains: a N-terminal domain that consist of tandem repeats of a glycine/ proline-rich sequence and a C-terminal galectin domain. - Galectin-4 [6], which is composed of two galectin domains. - Galectin-5. - Galectin-7 [7], a keratinocyte protein which could be involved in cell-cell and/or cell-matrix interactions necessary for normal growth control. - Galectin-8 [8], which is composed of two galectin domains. - Galectin-9 [9], which is composed of two galectin domains. - Human eosinophil lysophospholipase (EC 3.1.1.5) [5] (Charcot-Leyden crystal protein), a protein that may have both an enzymatic and a lectin activities. It forms hexagonal bipyramidal crystals in tissues and secretions from sites of eosinophil-associated inflammation. - Caenorhabditis elegans 32 Kd lactose-binding lectin [10]. This lectin is composed of two galectin domains. - Caenorhabditis elegans lec-7 and lec-8. The profile we developed covers the entire galectin domain. -Sequences known to belong to this class detected by the profile: ALL. -Other sequence(s) detected in Swiss-Prot: NONE. -Last update: March 2007 / Pattern removed, profile added and text revised. [ 1] Leffler H. "Introduction to galectins."; Trends Glycosci. Glycotechnol. 9:9-19(1997). [ 2] Leffler H., Carlsson S., Hedlund M., Qian Y., Poirier F. "Introduction to galectins." Glycoconj. J. 19:433-440(2004). PubMed=14758066; DOI=10.1023/B:GLYC.0000014072.34840.04 [ 3] Ban M., Yoon H.-J., Demirkan E., Utsumi S., Mikami B., Yagi F. "Structural basis of a fungal galectin from Agrocybe cylindracea for recognizing sialoconjugate." J. Mol. Biol. 351:695-706(2005). PubMed=16051274; DOI=10.1016/j.jmb.2005.06.045 [ 4] Lobsanov Y.D., Gitt M.A., Leffler H., Barondes S.H., Rini J.M. "X-ray crystal structure of the human dimeric S-Lac lectin, L-14-II, in complex with lactose at 2.9-A resolution." J. Biol. Chem. 268:27034-27038(1993). PubMed=8262940 [ 5] Leonidas D.D., Elbert B.L., Zhou Z., Leffler H., Ackerman S.J., Acharya K.R. "Crystal structure of human Charcot-Leyden crystal protein, an eosinophil lysophospholipase, identifies it as a new member of the carbohydrate-binding family of galectins." Structure 3:1379-1393(1995). PubMed=8747464 [ 6] Oda Y., Herrmann J., Gitt M.A., Turck C.W., Burlingame A.L., Barondes S.H., Leffler H. "Soluble lactose-binding lectin from rat intestine with two different carbohydrate-binding domains in the same peptide chain." J. Biol. Chem. 268:5929-5939(1993). PubMed=8449956 [ 7] Madsen P., Rasmussen H.H., Flint T., Gromov P., Kruse T.A., Honore B., Vorum H., Celis J.E. "Cloning, expression, and chromosome mapping of human galectin-7." J. Biol. Chem. 270:5823-5829(1995). PubMed=7534301 [ 8] Hadari Y.R., Paz K., Dekel R., Mestrovic T., Accili D., Zick Y. "Galectin-8. A new rat lectin, related to galectin-4." J. Biol. Chem. 270:3447-3453(1995). PubMed=7852431 [ 9] Wada J., Kanwar Y.S. "Identification and characterization of galectin-9, a novel beta-galactoside-binding mammalian lectin." J. Biol. Chem. 272:6078-6086(1997). PubMed=9038233 [10] Hirabayashi J., Satoh M., Kasai K.-I. "Evidence that Caenorhabditis elegans 32-kDa beta-galactoside-binding protein is homologous to vertebrate beta-galactoside-binding lectins. cDNA cloning and deduced amino acid sequence." J. Biol. Chem. 267:15485-15490(1992). PubMed=1639789 [11] Abbott W.M., Feizi T. J. Biol. Chem. 266:5552-5557(1991). -------------------------------------------------------------------------------- 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}