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From Proteopedia
CRYSTAL STRUCTURE OF HLA-B*2709 COMPLEXED WITH THE SELF-PEPTIDE TIS FROM EGF-RESPONSE FACTOR 1
Structural highlights
Disease[1B27_HUMAN] Defects in HLA-B are a cause of susceptibility to spondyloarthropathy type 1 (SPDA1) [MIM:106300]. It is a chronic rheumatic disease with multifactorial inheritance. It includes a spectrum of related disorders comprising ankylosing spondylitis, a subset of psoriatic arthritis, reactive arthritis (e.g. Reiter syndrome), arthritis associated with inflammatory bowel disease and undifferentiated spondyloarthropathy. These disorders may occur simultaneously or sequentially in the same patient, probably representing various phenotypic expressions of the same disease. Ankylosing spondylitis is the form of rheumatoid arthritis affecting the spine and is considered the prototype of seronegative spondyloarthropathies. It produces pain and stiffness as a result of inflammation of the sacroiliac, intervertebral, and costovertebral joints. Note=In the Greek Cypriot population, a restricted number of HLA-B27 subtypes are associated with ankylosing spondylitis and other B27-related diseases and an elevated frequency of the B*2702 allele in ankylosing spondylitis patients is identified. The allele B*2707 seems to have a protective role in this population because it was found only in the healthy controls.[1] Function[1B27_HUMAN] Involved in the presentation of foreign antigens to the immune system. [TISD_HUMAN] Probable regulatory protein involved in regulating the response to growth factors. RNA-binding protein that binds to 5'UUAUUUAUUU-3' core sequence. Binds to the class II AU-rich element (ARE) in the 3'-UTR of target mRNAs and promotes their deadenylation and degradation. 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 PubMedThe F pocket of major histocompatibility complex (in humans HLA) class I molecules accommodates the C terminus of the bound peptide. Residues forming this pocket exhibit considerable polymorphism, and a single difference (Asp116 in HLA-B*2705 and His116 in HLA-B*2709 heavy chains) confers differential association of these two HLA-B27 subtypes to the autoimmune disease ankylosing spondylitis. As peptide presentation by HLA molecules is of central importance for immune responses, we performed thermodynamic (circular dichroism, differential scanning calorimetry, fluorescence polarization) and X-ray crystallographic analyses of both HLA-B27 subtypes complexed with the epidermal growth factor response factor 1-derived self-peptide TIS (RRLPIFSRL) to understand the impact of the Asp116His exchange on peptide display. This peptide is known to be presented in vivo by both subtypes, and as expected for a self-peptide, TIS-reactive cytotoxic T lymphocytes are absent in the respective individuals. The thermodynamic analyses reveal that both HLA-B27:TIS complexes exhibit comparable, relatively high thermostability (Tm approximately 60 degrees C) and undergo multi-step unfolding reactions, with dissociation of the peptide in the first step. As shown by X-ray crystallography, only subtle structural differences between the subtypes were observed regarding the architecture of their F pockets, including the presence of distinct networks of water molecules. However, no consistent structural differences were found between the peptide presentation modes. In contrast to other peptides displayed by the two HLA-subtypes which show either structural or dynamical differences in their peptide presentation modes, the TIS-complexed HLA-B*2705 and HLA-B*2709 subtypes are an example for thermodynamic and structural equivalence, in agreement with functional data. Thermodynamic and structural equivalence of two HLA-B27 subtypes complexed with a self-peptide.,Hulsmeyer M, Welfle K, Pohlmann T, Misselwitz R, Alexiev U, Welfle H, Saenger W, Uchanska-Ziegler B, Ziegler A J Mol Biol. 2005 Mar 11;346(5):1367-79. Epub 2005 Jan 28. PMID:15713487[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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