{PDOC51969} {PS51969; CBM39} {BEGIN} ******************************************************* * CBM39 (carbohydrate binding type-39) domain profile * ******************************************************* The enzymic degradation of insoluble polysaccharides is one of the most important reactions on earth. Despite this, glycoside hydrolases attack such polysaccharides relatively inefficiently as their target glycosidic bonds are often inaccessible to the active site of the appropriate enzymes. In order to overcome these problems, many of the glycoside hydrolases that utilize insoluble substrates are modular, comprising catalytic modules appended to one or more non-catalytic CBMs (carbohydrate-binding modules). CBMs promote the association of the enzyme with the substrate [1]. BetaGRPs, also called Gram-negative bacteria binding proteins (GNBPs), make up a family of insect pathogen recognition receptors that bind to beta-1,3- glucan, a structural component of fungal cell walls and bacterial surfaces. The protein-carbohydrate binding event triggers activation of serine protease cascades leading to the activation of the prophenoloxidase (proPO) pathway in the hemolymph and intracellular Toll signaling. The activated proPO pathway produces melanin that encapsulates pathogenic microorganisms, whereas the Toll pathway results in the expression of antimicrobial peptides and/or proteins. BetaGRPs consist of an N-terminal beta-1,3-glucan-recognition domain (N- betaGRP, also known as GNBP homologous domain) and a C-terminal glucanase-like domain, with the former reported to be responsible for the proPO cascade activation. N-betaGRP binds to Curdlan, a linear water-insoluble beta-1,3- glucan polysaccharide, and to laminarin, a water-soluble beta-1,3-glucan polysaccharide containing beta-1,6 branches. The N-betaGRP domain is classified as a CBM39 [E1] and is sufficient for agglutination of microorganisms and activation of the proPO cascade [2,3,4,5]. The N-betaGRP domain is comprised of 100 amino acid residues and has an immunoglobulin-like beta-sandwich fold composed of two antiparallel beta- sheets containing three and five beta-strands (see ) [2,3,4,5]. The profile we developed covers the entire CBM39 domain. -Sequences known to belong to this class detected by the profile: ALL. -Other sequence(s) detected in Swiss-Prot: NONE. -Last update: April 2021 / First entry. [ 1] Boraston A.B., Bolam D.N., Gilbert H.J., Davies G.J. "Carbohydrate-binding modules: fine-tuning polysaccharide recognition." Biochem. J. 382:769-781(2004). PubMed=15214846; DOI=10.1042/BJ20040892 [ 2] Takahasi K., Ochiai M., Horiuchi M., Kumeta H., Ogura K., Ashida M., Inagaki F. "Solution structure of the silkworm betaGRP/GNBP3 N-terminal domain reveals the mechanism for beta-1,3-glucan-specific recognition." Proc. Natl. Acad. Sci. U. S. A. 106:11679-11684(2009). PubMed=19561300; DOI=10.1073/pnas.0901671106 [ 3] Mishima Y., Quintin J., Aimanianda V., Kellenberger C., Coste F., Clavaud C., Hetru C., Hoffmann J.A., Latge J.P., Ferrandon D., Roussel A. "The N-terminal domain of Drosophila Gram-negative binding protein 3 (GNBP3) defines a novel family of fungal pattern recognition receptors." J. Biol. Chem. 284:28687-28697(2009). PubMed=19692333; DOI=10.1074/jbc.M109.034587 [ 4] Kanagawa M., Satoh T., Ikeda A., Adachi Y., Ohno N., Yamaguchi Y. "Structural insights into recognition of triple-helical beta-glucans by an insect fungal receptor." J. Biol. Chem. 286:29158-29165(2011). PubMed=21697086; DOI=10.1074/jbc.M111.256701 [ 5] Dai H., Hiromasa Y., Takahashi D., VanderVelde D., Fabrick J.A., Kanost M.R., Krishnamoorthi R. "An initial event in the insect innate immune response: structural and biological studies of interactions between beta-1,3-glucan and the N-terminal domain of beta-1,3-glucan recognition protein." Biochemistry 52:161-170(2013). PubMed=23237493; DOI=10.1021/bi301440p [E1] http://www.cazy.org/CBM39.html -------------------------------------------------------------------------------- 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}