crystal structure of HLA B*3508 LPEP157A, HLA mutant Ala157crystal structure of HLA B*3508 LPEP157A, HLA mutant Ala157

Structural highlights

3vfo is a 3 chain structure with sequence from Homo sapiens and Human herpesvirus 4 strain B95-8. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:X-ray diffraction, Resolution 1.7Å
Resources:FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

BZLF1_EBVB9 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).[1] [2] [3] [4] [5]

Publication Abstract from PubMed

While the Major Histocompatibility Complex Class I (MHC-I) molecules typically bind short peptide (p) fragments (8-10 amino acids in length), longer, bulged, peptides are often be presented by MHC-I. Such bulged pMHC-I complexes represent challenges for T-cell receptor (TCR) ligation, although the general principles underscoring the interaction between TCRs and bulged pMHC-I complexes are unclear. To address this, we have explored the energetic basis of how an immunodominant TCR (termed SB27) binds to a 13 amino acid viral peptide (LPEPLPQGQLTAY) complexed to Human Leukocyte Antigen (HLA) B*3508. Using the crystal structure of the SB27 TCR-HLA B*3508LPEP complex as a guide, we undertook a comprehensive alanine-scanning mutagenesis approach at the TCR-pMHC-I interface and examined the effect of the mutations by biophysical (affinity measurements) and cellular approaches (tetramer staining). While the structural footprint on the HLA B*3508 was small, the energetic footprint was even smaller in that only two HLA B*3508 residues were critical for the TCR interaction. Instead, the energetic basis of this TCR-pMHC-I interaction was attributed to peptide-mediated interactions in which the complementarity determining region (CDR) 3alpha and germline encoded CDR1beta loops of the SB27 TCR played the principal role. Our findings highlight the peptide-centricity of TCR ligation towards a bulged pMHC-I complex.

The energetic basis underpinning T-cell teceptor tecognition of a super-bulged peptide bound to a major histocompatibility complex class I molecule.,Liu YC, Chen Z, Burrows SR, Purcell AW, McCluskey J, Rossjohn J, Gras S J Biol Chem. 2012 Feb 16. PMID:22343629[6]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

See Also

References

  1. Packham G, Economou A, Rooney CM, Rowe DT, Farrell PJ. Structure and function of the Epstein-Barr virus BZLF1 protein. J Virol. 1990 May;64(5):2110-6. PMID:2157874
  2. Kouzarides T, Packham G, Cook A, Farrell PJ. The BZLF1 protein of EBV has a coiled coil dimerisation domain without a heptad leucine repeat but with homology to the C/EBP leucine zipper. Oncogene. 1991 Feb;6(2):195-204. PMID:1847997
  3. Schepers A, Pich D, Hammerschmidt W. A transcription factor with homology to the AP-1 family links RNA transcription and DNA replication in the lytic cycle of Epstein-Barr virus. EMBO J. 1993 Oct;12(10):3921-9. PMID:8404860
  4. Wen W, Iwakiri D, Yamamoto K, Maruo S, Kanda T, Takada K. Epstein-Barr virus BZLF1 gene, a switch from latency to lytic infection, is expressed as an immediate-early gene after primary infection of B lymphocytes. J Virol. 2007 Jan;81(2):1037-42. Epub 2006 Nov 1. PMID:17079287 doi:10.1128/JVI.01416-06
  5. McDonald CM, Petosa C, Farrell PJ. Interaction of Epstein-Barr virus BZLF1 C-terminal tail structure and core zipper is required for DNA replication but not for promoter transactivation. J Virol. 2009 Apr;83(7):3397-401. doi: 10.1128/JVI.02500-08. Epub 2009 Jan 14. PMID:19144704 doi:10.1128/JVI.02500-08
  6. Liu YC, Chen Z, Burrows SR, Purcell AW, McCluskey J, Rossjohn J, Gras S. The energetic basis underpinning T-cell teceptor tecognition of a super-bulged peptide bound to a major histocompatibility complex class I molecule. J Biol Chem. 2012 Feb 16. PMID:22343629 doi:10.1074/jbc.M112.344689

3vfo, resolution 1.70Å

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