2hla: Difference between revisions

[[Image:2hla.gif|left|200px]]<br /><applet load="2hla" size="350" color="white" frame="true" align="right" spinBox="true"  

We have determined the structure of a second human histocompatibility glycoprotein, HLA-Aw68, by X-ray crystallography and refined it to a resolution of 2.6 A. Overall, the structure is extremely similar to that of HLA-A2 (refs 1, 2; and M.A.S. et al., manuscript in preparation), although the 11 amino-acid substitutions at polymorphic residues in the antigen-binding cleft alter the detailed shape and electrostatic charge of that site. A prominent negatively charged pocket within the cleft extends underneath the alpha-helix of the alpha 1-domain, providing a potential subsite for recognizing a positively charged side chain or peptide N terminus. Uninterpreted electron density, presumably representing an unknown 'antigen(s)', which seems to be different from that seen in the HLA-A2 structure, occupies the cleft and extends into the negatively charged pocket in HLA-Aw68. The structures of HLA-Aw68 and HLA-A2 demonstrate how polymorphism creates and alters subsites (pockets) positioned to bind peptide side chains, thereby suggesting the structural basis for allelic specificity in foreign antigen binding.

2HLA is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. The following page contains interesting information on the relation of 2HLA with [[http://pdb.rcsb.org/pdb/static.do?p=education_discussion/molecule_of_the_month/pdb62_1.html Major Histocompatibility Complex]]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2HLA OCA].  

[[Category: Garrett, T P.J.]]

[[Category: Saper, M A.]]

[[Category: Wiley, D C.]]

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