Dataset Information

Structure of S-lectin, a developmentally regulated vertebrate beta-galactoside-binding protein.

ABSTRACT: The crystal structure of a 14-kDa bovine spleen S-lectin complexed with the disaccharide N-acetyllactosamine at 1.9-A resolution reveals a surprising structural relationship to legume lectins, despite the lack of sequence homology. Two monomers associate to form an extended beta-sandwich, each with the same jelly roll topology typical of legume lectins but with dramatically trimmed loops and with different dimer association. Each monomer binds one N-acetyllactosamine molecule in a topologically and spatially different site than that of legume lectins. The carbohydrate-binding site provides an unprecedented paradigm for carbohydrate binding, with a unique network of salt bridges. The specificity for beta-galactose arises from intricate interactions that constrain the position of the O4 atom.

SUBMITTER: Liao DI

PROVIDER: S-EPMC43172 | biostudies-other | 1994 Feb

REPOSITORIES: biostudies-other

ACCESS DATA

Publications

Structure of S-lectin, a developmentally regulated vertebrate beta-galactoside-binding protein.

Liao D I DI Kapadia G G Ahmed H H Vasta G R GR Herzberg O O

Proceedings of the National Academy of Sciences of the United States of America 19940201 4

The crystal structure of a 14-kDa bovine spleen S-lectin complexed with the disaccharide N-acetyllactosamine at 1.9-A resolution reveals a surprising structural relationship to legume lectins, despite the lack of sequence homology. Two monomers associate to form an extended beta-sandwich, each with the same jelly roll topology typical of legume lectins but with dramatically trimmed loops and with different dimer association. Each monomer binds one N-acetyllactosamine molecule in a topologically ...[more]

PMID: 8108426

Similar Datasets

Project description:UnlabelledMammalian lipopolysaccharide (LPS) binding proteins (LBPs) occur mainly in extracellular fluids and promote LPS delivery to specific host cell receptors. The function of LBPs has been studied principally in the context of host defense; the possible role of LBPs in nonpathogenic host-microbe interactions has not been well characterized. Using the Euprymna scolopes-Vibrio fischeri model, we analyzed the structure and function of an LBP family protein, E. scolopes LBP1 (EsLBP1), and provide evidence for its role in triggering a symbiont-induced host developmental program. Previous studies showed that, during initial host colonization, the LPS of V. fischeri synergizes with peptidoglycan (PGN) monomer to induce morphogenesis of epithelial tissues of the host animal. Computationally modeled EsLBP1 shares some but not all structural features of mammalian LBPs that are thought important for LPS binding. Similar to human LBP, recombinant EsLBP1 expressed in insect cells bound V. fischeri LPS and Neisseria meningitidis lipooligosaccharide (LOS) with nanomolar or greater affinity but bound Francisella tularensis LPS only weakly and did not bind PGN monomer. Unlike human LBP, EsLBP1 did not bind N. meningitidis LOS:CD14 complexes. The eslbp1 transcript was upregulated ~22-fold by V. fischeri at 24 h postinoculation. Surprisingly, this upregulation was not induced by exposure to LPS but, rather, to the PGN monomer alone. Hybridization chain reaction-fluorescent in situ hybridization (HCR-FISH) and immunocytochemistry (ICC) localized eslbp1 transcript and protein in crypt epithelia, where V. fischeri induces morphogenesis. The data presented here provide a window into the evolution of LBPs and the scope of their roles in animal symbioses.ImportanceMammalian lipopolysaccharide (LPS)-binding protein (LBP) is implicated in conveying LPS to host cells and potentiating its signaling activity. In certain disease states, such as obesity, the overproduction of this protein has been a reliable biomarker of chronic inflammation. Here, we describe a symbiosis-induced invertebrate LBP whose tertiary structure and LPS-binding characteristics are similar to those of mammalian LBPs; however, the primary structure of this distantly related squid protein (EsLBP1) differs in key residues previously believed to be essential for LPS binding, suggesting that an alternative strategy exists. Surprisingly, symbiotic expression of eslbp1 is induced by peptidoglycan derivatives, not LPS, a pattern converse to that of RegIIIγ, an important mammalian immunity protein that binds peptidoglycan but whose gene expression is induced by LPS. Finally, EsLBP1 occurs along the apical surfaces of all the host's epithelia, suggesting that it was recruited from a general defensive role to one that mediates specific interactions with its symbiont.

Dataset Information

Structure of S-lectin, a developmentally regulated vertebrate beta-galactoside-binding protein.

Publications

Structure of S-lectin, a developmentally regulated vertebrate beta-galactoside-binding protein.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets