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1t7v
From Proteopedia
| 1t7v, resolution 1.95Å () | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Sites: | , , and | ||||||||
| Ligands: | , | ||||||||
| Gene: | AZGP1, ZAG, ZNGP1 (Homo sapiens) | ||||||||
| Related: | 1zag, 1t7w, 1t7x, 1t7y, 1t7z, 1t80 | ||||||||
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| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||||
Zn-alpha-2-glycoprotein; baculo-ZAG PEG 200
Zn-alpha2-glycoprotein (ZAG) is a 41 kDa soluble protein that is present in most bodily fluids. The previously reported 2.8 A crystal structure of ZAG isolated from human serum demonstrated the structural similarity between ZAG and class I major histocompatibility complex (MHC) molecules and revealed a non-peptidic ligand in the ZAG counterpart of the MHC peptide-binding groove. Here we present crystallographic studies to explore further the nature of the non-peptidic ligand in the ZAG groove. Comparison of the structures of several forms of recombinant ZAG, including a 1.95 A structure derived from ZAG expressed in insect cells, suggests that the non-peptidic ligand in the current structures and in the structure of serum ZAG is a polyethylene glycol (PEG), which is present in the crystallization conditions used. Further support for PEG binding in the ZAG groove is provided by the finding that PEG displaces a fluorophore-tagged fatty acid from the ZAG binding site. From these results we hypothesize that our purified forms of ZAG do not contain a bound endogenous ligand, but that the ZAG groove is capable of binding hydrophobic molecules, which may relate to its function.
Crystallographic studies of ligand binding by Zn-alpha2-glycoprotein., Delker SL, West AP Jr, McDermott L, Kennedy MW, Bjorkman PJ, J Struct Biol. 2004 Nov;148(2):205-13. PMID:15477100
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
About this Structure
1t7v is a 1 chain structure with sequence from Homo sapiens. Full crystallographic information is available from OCA.
Reference
- Delker SL, West AP Jr, McDermott L, Kennedy MW, Bjorkman PJ. Crystallographic studies of ligand binding by Zn-alpha2-glycoprotein. J Struct Biol. 2004 Nov;148(2):205-13. PMID:15477100 doi:10.1016/j.jsb.2004.04.009
- Sanchez LM, Chirino AJ, Bjorkman P. Crystal structure of human ZAG, a fat-depleting factor related to MHC molecules. Science. 1999 Mar 19;283(5409):1914-9. PMID:10206894
