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From Proteopedia
Crystal Structure of SB47 TCR-HLA B*3505-LPEP complex
Structural highlights
Disease[B2MG_HUMAN] Defects in B2M are the cause of hypercatabolic hypoproteinemia (HYCATHYP) [MIM:241600]. Affected individuals show marked reduction in serum concentrations of immunoglobulin and albumin, probably due to rapid degradation.[1] Note=Beta-2-microglobulin may adopt the fibrillar configuration of amyloid in certain pathologic states. The capacity to assemble into amyloid fibrils is concentration dependent. Persistently high beta(2)-microglobulin serum levels lead to amyloidosis in patients on long-term hemodialysis.[2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13] [14] Function[C5MK56_HUMAN] Involved in the presentation of foreign antigens to the immune system (By similarity).[SAAS:SAAS003006_004_004364] [BZLF1_EBVG] Plays a key role in the switch from latent infection to lytic cycle producing new virions. Acts as a transcription factor, inducing early lytic cycle genes, and as a origin binding protein for genome replication. BZLF1 activates the promoter of another EBV gene (BSLF2+BMLF1) (By similarity). [B2MG_HUMAN] Component of the class I major histocompatibility complex (MHC). Involved in the presentation of peptide antigens to the immune system. Publication Abstract from PubMedHuman leukocyte antigen (HLA)-I molecules can present long peptides, yet the mechanisms by which T-cell receptors (TCRs) recognize featured pHLA-I landscapes are unclear. We compared the binding modes of three distinct human TCRs, CA5, SB27, and SB47, complexed with a "super-bulged" viral peptide (LPEPLPQGQLTAY) restricted by HLA-B*35:08. The CA5 and SB27 TCRs engaged HLA-B*35:08(LPEP) similarly, straddling the central region of the peptide but making limited contacts with HLA-B*35:08. Remarkably, the CA5 TCR did not contact the alpha1-helix of HLA-B*35:08. Differences in the CDR3beta loop between the CA5 and SB27 TCRs caused altered fine specificities. Surprisingly, the SB47 TCR engaged HLA-B*35:08(LPEP) using a completely distinct binding mechanism, namely "bypassing" the bulged peptide and making extensive contacts with the extreme N-terminal end of HLA-B*35:08. This docking footprint included HLA-I residues not observed previously as TCR contact sites. The three TCRs exhibited differing patterns of alloreactivity toward closely related or distinct HLA-I allotypes. Thus, the human T-cell repertoire comprises a range of TCRs that can interact with "bulged" pHLA-I epitopes using unpredictable strategies, including the adoption of atypical footprints on the MHC-I. Highly divergent T-cell receptor binding modes underlie specific recognition of a bulged viral peptide bound to a human leukocyte antigen class I molecule.,Liu YC, Miles JJ, Neller MA, Gostick E, Price DA, Purcell AW, McCluskey J, Burrows SR, Rossjohn J, Gras S J Biol Chem. 2013 May 31;288(22):15442-54. doi: 10.1074/jbc.M112.447185. Epub, 2013 Apr 8. PMID:23569211[15] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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Categories: Human | Gras, S | Liu, Y C | Rossjohn, J | Alloreactivity | Ebv | Hla b*3508 | Immune system | Lpep | T cell | Tcr
