View source for 1tmc


==THE THREE-DIMENSIONAL STRUCTURE OF A CLASS I MAJOR HISTOCOMPATIBILITY COMPLEX MOLECULE MISSING THE ALPHA3 DOMAIN OF THE HEAVY CHAIN==
<StructureSection load='1tmc' size='340' side='right'caption='[[1tmc]], [[Resolution|resolution]] 2.30&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1tmc]] is a 3 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1TMC OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1TMC FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2.3&#8491;</td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=1tmc FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1tmc OCA], [https://pdbe.org/1tmc PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1tmc RCSB], [https://www.ebi.ac.uk/pdbsum/1tmc PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1tmc ProSAT]</span></td></tr>
</table>
== Disease ==
[https://www.uniprot.org/uniprot/HLAA_HUMAN HLAA_HUMAN] Birdshot chorioretinopathy. Alleles A*02:01 and A*24:02 are associated with increased susceptibility to diabetes mellitus, insulin-dependent (IDDM) (PubMed:16731854, PubMed:18802479, PubMed:22245737, PubMed:22522618). In a glucose-dependent way, allele A*02:01 may aberrantly present the signal peptide of preproinsulin (ALWGPDPAAA) on the surface of pancreatic beta cells to autoreactive CD8-positive T cells, potentially driving T-cell mediated cytotoxicity in pancreatic islets (PubMed:18802479, PubMed:22245737). Allele A*24:02 may present the signal peptide of preproinsulin (LWMRLLPLL) and contribute to acute pancreatic beta-cell destruction and early onset of IDDM (PubMed:16731854, PubMed:22522618).<ref>PMID:16731854</ref> <ref>PMID:18802479</ref> <ref>PMID:22245737</ref> <ref>PMID:22522618</ref>   Allele A*03:01 is associated with increased susceptibility to multiple sclerosis (MS), an autoimmune disease of the central nervous system (PubMed:10746785). May contribute to the initiation phase of the disease by presenting myelin PLP1 self-peptide (KLIETYFSK) to autoreactive CD8-positive T cells capable of initiating the first autoimmune attacks (PubMed:18953350).<ref>PMID:10746785</ref> <ref>PMID:18953350</ref>   Allele A*26:01 is associated with increased susceptibility to Behcet disease (BD) in the Northeast Asian population. Especially in the HLA-B*51-negative BD populations, HLA-A*26 is significantly associated with the onset of BD.<ref>PMID:30872678</ref>   Allele A*29:02 is associated with increased susceptibility to birdshot chorioretinopathy (BSCR). May aberrantly present retinal autoantigens and induce autoimmune uveitis.<ref>PMID:1728143</ref> 
== Function ==
[https://www.uniprot.org/uniprot/HLAA_HUMAN HLAA_HUMAN] Antigen-presenting major histocompatibility complex class I (MHCI) molecule. In complex with B2M/beta 2 microglobulin displays primarily viral and tumor-derived peptides on antigen-presenting cells for recognition by alpha-beta T cell receptor (TCR) on HLA-A-restricted CD8-positive T cells, guiding antigen-specific T cell immune response to eliminate infected or transformed cells (PubMed:10449296, PubMed:12138174, PubMed:12393434, PubMed:1402688, PubMed:15893615, PubMed:17189421, PubMed:19543285, PubMed:21498667, PubMed:24192765, PubMed:24395804, PubMed:2456340, PubMed:2784196, PubMed:28250417, PubMed:7504010, PubMed:7694806, PubMed:9862734). May also present self-peptides derived from the signal sequence of secreted or membrane proteins, although T cells specific for these peptides are usually inactivated to prevent autoreactivity (PubMed:25880248, PubMed:7506728, PubMed:7679507). Both the peptide and the MHC molecule are recognized by TCR, the peptide is responsible for the fine specificity of antigen recognition and MHC residues account for the MHC restriction of T cells (PubMed:12796775, PubMed:18275829, PubMed:19542454, PubMed:28250417). Typically presents intracellular peptide antigens of 8 to 13 amino acids that arise from cytosolic proteolysis via IFNG-induced immunoproteasome or via endopeptidase IDE/insulin-degrading enzyme (PubMed:17079320, PubMed:17189421, PubMed:20364150, PubMed:26929325, PubMed:27049119). Can bind different peptides containing allele-specific binding motifs, which are mainly defined by anchor residues at position 2 and 9 (PubMed:7504010, PubMed:9862734).<ref>PMID:10449296</ref> <ref>PMID:12138174</ref> <ref>PMID:12393434</ref> <ref>PMID:12796775</ref> <ref>PMID:1402688</ref> <ref>PMID:15893615</ref> <ref>PMID:17079320</ref> <ref>PMID:17189421</ref> <ref>PMID:18275829</ref> <ref>PMID:19542454</ref> <ref>PMID:19543285</ref> <ref>PMID:20364150</ref> <ref>PMID:21498667</ref> <ref>PMID:24192765</ref> <ref>PMID:24395804</ref> <ref>PMID:2456340</ref> <ref>PMID:25880248</ref> <ref>PMID:26929325</ref> <ref>PMID:27049119</ref> <ref>PMID:2784196</ref> <ref>PMID:28250417</ref> <ref>PMID:7504010</ref> <ref>PMID:7506728</ref> <ref>PMID:7679507</ref> <ref>PMID:7694806</ref> <ref>PMID:9862734</ref>   Allele A*01:01: Presents a restricted peptide repertoire including viral epitopes derived from IAV NP/nucleoprotein (CTELKLSDY), IAV PB1/polymerase basic protein 1 (VSDGGPNLY), HAdV-11 capsid L3/hexon protein (LTDLGQNLLY), SARS-CoV-2 3a/ORF3a (FTSDYYQLY) as well as tumor peptide antigens including MAGE1 (EADPTGHSY), MAGEA3 (EVDPIGHLY) and WT1 (TSEKRPFMCAY), all having in common a canonical motif with a negatively charged Asp or Glu residue at position 3 and a Tyr anchor residue at the C-terminus (PubMed:1402688, PubMed:17189421, PubMed:19177349, PubMed:20364150, PubMed:24395804, PubMed:25880248, PubMed:26758806, PubMed:30530481, PubMed:32887977, PubMed:7504010). A number of HLA-A*01:01-restricted peptides carry a post-translational modification with oxidation and N-terminal acetylation being the most frequent (PubMed:25880248). Fails to present highly immunogenic peptides from the EBV latent antigens (PubMed:18779413).<ref>PMID:1402688</ref> <ref>PMID:17189421</ref> <ref>PMID:18779413</ref> <ref>PMID:19177349</ref> <ref>PMID:20364150</ref> <ref>PMID:24395804</ref> <ref>PMID:25880248</ref> <ref>PMID:26758806</ref> <ref>PMID:30530481</ref> <ref>PMID:7504010</ref>   Allele A*02:01: A major allele in human populations, presents immunodominant viral epitopes derived from IAV M/matrix protein 1 (GILGFVFTL), HIV-1 env (TLTSCNTSV), HIV-1 gag-pol (ILKEPVHGV), HTLV-1 Tax (LLFGYPVYV), HBV C/core antigen (FLPSDFFPS), HCMV UL83/pp65 (NLVPMVATV) as well as tumor peptide antigens including MAGEA4 (GVYDGREHTV), WT1 (RMFPNAPYL) and CTAG1A/NY-ESO-1 (SLLMWITQC), all having in common hydrophobic amino acids at position 2 and at the C-terminal anchors.<ref>PMID:11502003</ref> <ref>PMID:12138174</ref> <ref>PMID:12796775</ref> <ref>PMID:17079320</ref> <ref>PMID:18275829</ref> <ref>PMID:19542454</ref> <ref>PMID:20619457</ref> <ref>PMID:22245737</ref> <ref>PMID:26929325</ref> <ref>PMID:2784196</ref> <ref>PMID:28250417</ref> <ref>PMID:7694806</ref> <ref>PMID:7935798</ref> <ref>PMID:8630735</ref> <ref>PMID:8805302</ref> <ref>PMID:8906788</ref> <ref>PMID:9177355</ref>   Allele A*03:01: Presents viral epitopes derived from IAV NP (ILRGSVAHK), HIV-1 nef (QVPLRPMTYK), HIV-1 gag-pol (AIFQSSMTK), SARS-CoV-2 N/nucleoprotein (KTFPPTEPK) as well as tumor peptide antigens including PMEL (LIYRRRLMK), NODAL (HAYIQSLLK), TRP-2 (RMYNMVPFF), all having in common hydrophobic amino acids at position 2 and Lys or Arg anchor residues at the C-terminus (PubMed:19543285, PubMed:21943705, PubMed:2456340, PubMed:32887977, PubMed:7504010, PubMed:7679507, PubMed:9862734). May also display spliced peptides resulting from the ligation of two separate proteasomal cleavage products that are not contiguous in the parental protein (PubMed:27049119).<ref>PMID:19543285</ref> <ref>PMID:21943705</ref> <ref>PMID:2456340</ref> <ref>PMID:27049119</ref> <ref>PMID:7504010</ref> <ref>PMID:7679507</ref> <ref>PMID:9862734</ref>   Allele A*11:01: Presents several immunodominant epitopes derived from HIV-1 gag-pol and HHV-4 EBNA4, containing the peptide motif with Val, Ile, Thr, Leu, Tyr or Phe at position 2 and Lys anchor residue at the C-terminus. Important in the control of HIV-1, EBV and HBV infections (PubMed:10449296). Presents an immunodominant epitope derived from SARS-CoV-2 N/nucleoprotein (KTFPPTEPK) (PubMed:32887977).<ref>PMID:10449296</ref> <ref>PMID:32887977</ref>   Allele A*23:01: Interacts with natural killer (NK) cell receptor KIR3DL1 and may contribute to functional maturation of NK cells and self-nonself discrimination during innate immune response.<ref>PMID:17182537</ref>   Allele A*24:02: Presents viral epitopes derived from HIV-1 nef (RYPLTFGWCF), EBV lytic- and latent-cycle antigens BRLF1 (TYPVLEEMF), BMLF1 (DYNFVKQLF) and LMP2 (IYVLVMLVL), SARS-CoV nucleocapsid/N (QFKDNVILL), as well as tumor peptide antigens including PRAME (LYVDSLFFL), all sharing a common signature motif, namely an aromatic residue Tyr or Phe at position 2 and a nonhydrophobic anchor residue Phe, Leu or Iso at the C-terminus (PubMed:12393434, PubMed:20844028, PubMed:24192765, PubMed:9047241). Interacts with natural killer (NK) cell receptor KIR3DL1 and may contribute to functional maturation of NK cells and self-nonself discrimination during innate immune response (PubMed:17182537, PubMed:18502829).<ref>PMID:12393434</ref> <ref>PMID:17182537</ref> <ref>PMID:18502829</ref> <ref>PMID:20844028</ref> <ref>PMID:24192765</ref> <ref>PMID:9047241</ref>   Allele A*26:01: Presents several epitopes derived from HIV-1 gag-pol (EVIPMFSAL, ETKLGKAGY) and env (LVSDGGPNLY), carrying as anchor residues preferentially Glu at position 1, Val or Thr at position 2 and Tyr at the C-terminus.<ref>PMID:15893615</ref>   Allele A*29:02: Presents peptides having a common motif, namely a Glu residue at position 2 and Tyr or Leu anchor residues at the C-terminus.<ref>PMID:8622959</ref>   Allele A*32:01: Interacts with natural killer (NK) cell receptor KIR3DL1 and may contribute to functional maturation of NK cells and self-nonself discrimination during innate immune response.<ref>PMID:17182537</ref>   Allele A*68:01: Presents viral epitopes derived from IAV NP (KTGGPIYKR) and HIV-1 tat (ITKGLGISYGR), having a common signature motif namely, Val or Thr at position 2 and positively charged residues Arg or Lys at the C-terminal anchor.<ref>PMID:1448153</ref> <ref>PMID:1448154</ref> <ref>PMID:2784196</ref>   Allele A*74:01: Presents immunodominant HIV-1 epitopes derived from gag-pol (GQMVHQAISPR, QIYPGIKVR) and rev (RQIHSISER), carrying an aliphatic residue at position 2 and Arg anchor residue at the C-terminus. May contribute to viral load control in chronic HIV-1 infection.<ref>PMID:21498667</ref> 
== Evolutionary Conservation ==
[[Image:Consurf_key_small.gif|200px|right]]
Check<jmol>
  <jmolCheckbox>
    <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/tm/1tmc_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked>
    <text>to colour the structure by Evolutionary Conservation</text>
  </jmolCheckbox>
</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=1tmc ConSurf].
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== Publication Abstract from PubMed ==
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.

The three-dimensional structure of a class I major histocompatibility complex molecule missing the alpha 3 domain of the heavy chain.,Collins EJ, Garboczi DN, Karpusas MN, Wiley DC Proc Natl Acad Sci U S A. 1995 Feb 14;92(4):1218-21. PMID:7862664<ref>PMID:7862664</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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<div class="pdbe-citations 1tmc" style="background-color:#fffaf0;"></div>

==See Also==
*[[Beta-2 microglobulin 3D structures|Beta-2 microglobulin 3D structures]]
*[[MHC 3D structures|MHC 3D structures]]
*[[MHC I 3D structures|MHC I 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Collins EJ]]
[[Category: Garboczi DN]]
[[Category: Karpusas MN]]
[[Category: Wiley DC]]