1xz0
From Proteopedia
Crystal structure of CD1a in complex with a synthetic mycobactin lipopeptide
Structural highlights
FunctionCD1A_HUMAN Antigen-presenting protein that binds self and non-self lipid and glycolipid antigens and presents them to T-cell receptors on natural killer T-cells.[1] [2] [3] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedCD1a is expressed on Langerhans cells (LCs) and dendritic cells (DCs), where it mediates T cell recognition of glycolipid and lipopeptide antigens that contain either one or two alkyl chains. We demonstrate here that CD1a-restricted T cells can discriminate the peptide component of didehydroxymycobactin lipopeptides. Structure analysis of CD1a cocrystallized with a synthetic mycobactin lipopeptide at 2.8 A resolution further reveals that the single alkyl chain is inserted deep within the A' pocket of the groove, whereas its two peptidic branches protrude along the F' pocket to the outer, alpha-helical surface of CD1a for recognition by the TCR. Remarkably, the cyclized lysine branch of the peptide moiety lies in the shallow F' pocket in a conformation that closely mimics that of the alkyl chain in the CD1a-sulfatide structure. Thus, this structural study illustrates how a single chain lipid can be presented by CD1 and that the peptide moiety of the lipopeptide is recognized by the TCR. Molecular mechanism of lipopeptide presentation by CD1a.,Zajonc DM, Crispin MD, Bowden TA, Young DC, Cheng TY, Hu J, Costello CE, Rudd PM, Dwek RA, Miller MJ, Brenner MB, Moody DB, Wilson IA Immunity. 2005 Feb;22(2):209-19. PMID:15723809[4] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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Categories: Homo sapiens | Large Structures | Bowden TA | Cheng TY | Costello CE | Crispin MD | Hu J | Miller MJ | Moody DB | Wilson IA | Young DC | Zajonc DM
