2j3f
L-ficolin complexed to N-acetyl-D-galactosamineL-ficolin complexed to N-acetyl-D-galactosamine
Structural highlights
FunctionFCN2_HUMAN May function in innate immunity through activation of the lectin complement pathway. Calcium-dependent and GlcNAc-binding lectin. Enhances phagocytosis of S.typhimurium by neutrophils, suggesting an opsonic effect via the collagen region.[1] Evolutionary Conservation![]() Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedInnate immunity relies critically upon the ability of a few pattern recognition molecules to sense molecular markers on pathogens, but little is known about these interactions at the atomic level. Human L- and H-ficolins are soluble oligomeric defence proteins with lectin-like activity, assembled from collagen fibers prolonged by fibrinogen-like recognition domains. The X-ray structures of their trimeric recognition domains, alone and in complex with various ligands, have been solved to resolutions up to 1.95 and 1.7 A, respectively. Both domains have three-lobed structures with clefts separating the distal parts of the protomers. Ca(2+) ions are found at sites homologous to those described for tachylectin 5A (TL5A), an invertebrate lectin. Outer binding sites (S1) homologous to the GlcNAc-binding pocket of TL5A are present in the ficolins but show different structures and specificities. In L-ficolin, three additional binding sites (S2-S4) surround the cleft. Together, they define an unpredicted continuous recognition surface able to sense various acetylated and neutral carbohydrate markers in the context of extended polysaccharides such as 1,3-beta-D-glucan, as found on microbial or apoptotic surfaces. Structural insights into the innate immune recognition specificities of L- and H-ficolins.,Garlatti V, Belloy N, Martin L, Lacroix M, Matsushita M, Endo Y, Fujita T, Fontecilla-Camps JC, Arlaud GJ, Thielens NM, Gaboriaud C EMBO J. 2007 Jan 24;26(2):623-33. Epub 2007 Jan 11. PMID:17215869[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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