2j64
H-ficolinH-ficolin
Structural highlights
DiseaseFCN3_HUMAN Defects in FCN3 are the cause of ficolin 3 deficiency (FCN3D) [MIM:613860. FCN3D is a disorder characterized by immunodeficiency, recurrent infections, brain abscesses and recurrent warts on the fingers. Affected individuals have normal levels of lymphocytes, normal T-cell responses, and normal antibodies, but a selective deficient antibody response to pneumococcal polysaccharide vaccine.[1] FunctionFCN3_HUMAN May function in innate immunity through activation of the lectin complement pathway. Calcium-dependent and GlcNAc-binding lectin. Has affinity with GalNAc, GlcNAc, D-fucose, as mono/oligosaccharide and lipopolysaccharides from S.typhimurium and S.minnesota.[2] 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[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
|
|