6irl
From Proteopedia
Crystal structure of 8-mer peptide from avian influenza H5N1 virus in complex with BF2*1501
Structural highlights
Function[PA_I01A3] Plays an essential role in viral RNA transcription and replication by forming the heterotrimeric polymerase complex together with PB1 and PB2 subunits. The complex transcribes viral mRNAs by using a unique mechanism called cap-snatching. It consists in the hijacking and cleavage of host capped pre-mRNAs. These short capped RNAs are then used as primers for viral mRNAs. The PB2 subunit is responsible for the binding of the 5' cap of cellular pre-mRNAs which are subsequently cleaved after 10-13 nucleotides by the PA subunit that carries the endonuclease activity.[HAMAP-Rule:MF_04063] [B2MG_CHICK] Component of the class I major histocompatibility complex (MHC). Involved in the presentation of peptide antigens to the immune system. Publication Abstract from PubMedLethal infections by strains of the highly-pathogenic avian influenza virus (HPAIV) H5N1 pose serious threats to both the poultry industry and public health worldwide. A lack of confirmed HPAIV epitopes recognized by cytotoxic T lymphocytes (CTLs) has hindered the utilization of CD8(+) T-cell-mediated immunity and has precluded the development of effectively diversified epitope-based vaccination approaches. In particular, an HPAIV H5N1 CTL-recognized epitope based on the peptide MHC-I-beta2m (pMHC-I) complex has not yet been designed. Here, screening a collection of selected peptides of several HPAIV strains against a specific pathogen-free pMHC-I (pBF2*1501), we identified a highly-conserved HPAIV H5N1 CTL epitope, named HPAIV-PA123-130 We determined the structure of the BF2*1501-PA123-130 complex at 2.1 A resolution to elucidate the molecular mechanisms of a preferential presentation of the highly-conserved PA123-130 epitope in the chicken B15 lineage. Conformational characteristics of the PA123-130 epitope with a protruding Tyr-7 residue indicated that this epitope has great potential to be recognized by specific TCRs. Moreover, significantly increased numbers of CD8(+) T cells specific for the HPAIV-PA123-130 epitope in peptide-immunized chickens indicated that a repertoire of CD8(+) T cells can specifically respond to this epitope. We anticipate that the identification and structural characterization of the PA123-130 epitope reported here could enable further studies of CTL immunity against HPAIV H5N1. Such studies may aid in the development of vaccine development strategies using well-conserved internal viral antigens in chickens. Structures of the MHC-I molecule BF2*1501 disclose the preferred presentation of an H5N1 virus-derived epitope.,Li X, Zhang L, Liu Y, Ma L, Zhang N, Xia C J Biol Chem. 2020 Apr 17;295(16):5292-5306. doi: 10.1074/jbc.RA120.012713. Epub, 2020 Mar 9. PMID:32152225[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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Categories: Chick | Large Structures | Xiao, L | Zhang, L | 8-mer | Avian influenza virus | Chicken | Epitope | H5n1 | Immune system | Mhc class i
