1o7s: Difference between revisions

Sialic acid-binding immunoglobulin-like lectins (Siglecs) recognize, sialylated glycoconjugates and play a role in cell-cell recognition., Siglec-7 is expressed on natural killer cells and displays unique ligand, binding properties different from other members of the Siglec family. Here, we describe the high resolution structures of the N-terminal V-set Ig-like, domain of Siglec-7 in two crystal forms, at 1.75 and 1.9 A. The latter, crystal form reveals the full structure of this domain and allows us to, speculate on the differential ligand binding properties displayed by, members of the Siglec family. A fully ordered N-linked glycan is observed, tethered by tight interactions with symmetry-related protein molecules in, the crystal. Comparison of the structure with that of sialoadhesin and a, model of Siglec-9 shows that the unique preference of Siglec-7 for, alpha(2,8)-linked disialic acid is likely to reside in the C-C' loop, which is variable in the Siglec family. In the Siglec-7 structure, the, ligand-binding pocket is occupied by a loop of a symmetry-related, molecule, mimicking the interactions with sialic acid.

1O7S is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] with NAG, NDG and CYS as [http://en.wikipedia.org/wiki/ligands ligands]. Structure known Active Site: AC1. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1O7S OCA].  

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