2it5
From Proteopedia
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Crystal Structure of DCSIGN-CRD with man6
Overview
The dendritic cell surface receptor DC-SIGN and the closely related, endothelial cell receptor DC-SIGNR specifically recognize high mannose, N-linked carbohydrates on viral pathogens. Previous studies have shown, that these receptors bind the outer trimannose branch, Manalpha1-3[Manalpha1-6]Manalpha present in high mannose structures., Although the trimannoside binds to DC-SIGN or DC-SIGNR more strongly than, mannose, additional affinity enhancements are observed in the presence of, one or more Manalpha1-2Manalpha moieties on the nonreducing termini of, oligomannose structures. The molecular basis of this enhancement has been, investigated by determining crystal structures of DC-SIGN bound to a, synthetic six-mannose fragment of a high mannose N-linked oligosaccharide, Manalpha1-2Manalpha1-3[Manalpha1-2Manalpha1-6]Manalpha1-6Man and to the, disaccharide Manalpha1-2Man. The structures reveal mixtures of two binding, modes in each case. Each mode features typical C-type lectin binding at, the principal Ca2+-binding site by one mannose residue. In addition, other, sugar residues form contacts unique to each binding mode. These results, suggest that the affinity enhancement displayed toward oligosaccharides, decorated with the Manalpha1-2Manalpha structure is due in part to, multiple binding modes at the primary Ca2+ site, which provide both, additional contacts and a statistical (entropic) enhancement of binding.
About this Structure
2IT5 is a Single protein structure of sequence from Homo sapiens with CA as ligand. Full crystallographic information is available from OCA.
Reference
Multiple modes of binding enhance the affinity of DC-SIGN for high mannose N-linked glycans found on viral glycoproteins., Feinberg H, Castelli R, Drickamer K, Seeberger PH, Weis WI, J Biol Chem. 2007 Feb 9;282(6):4202-9. Epub 2006 Dec 6. PMID:17150970
Page seeded by OCA on Mon Nov 12 22:47:34 2007
