1tmc: Difference between revisions

[[Image:1tmc.jpg|left|200px]]

'''THE HTREE-DIMENSIONAL STRUCTURE OF A CLASS I MAJOR HISTOCOMPATIBILITY COMPLEX MOLECULE MISSING THE ALPHA3 DOMAIN OF THE HEAVY CHAIN'''

Class I major histocompatibility complex (MHC) molecules are ternary complexes of the soluble serum protein beta 2-microglobulin, MHC heavy chain, and bound peptide. The first two domains (alpha 1, alpha 2) of the heavy chain create the peptide binding cleft and the surface that contacts the T-cell receptor. The third domain (alpha 3) associates with the T-cell co-receptor, CD8, during T-cell recognition. Here we describe the x-ray crystal structure of a human class I MHC molecule, HLA-Aw68, from which the alpha 3 domain has been proteolytically removed. The resulting molecule shows no gross morphological changes compared to the intact protein. A decameric peptide complexed with the intact HLA-Aw68 is seen to bind to the proteolized molecule in the conventional manner, demonstrating that the alpha 3 domain is not required for the structural integrity of the molecule or for peptide binding.

''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sat May  3 10:07:33 2008''