Structural mechanism of tapasin-mediated MHC-I peptide loading in antigen presentation.
Nat Commun
; 13(1): 5470, 2022 09 17.
Article
em En
| MEDLINE
| ID: mdl-36115831
ABSTRACT
Loading of MHC-I molecules with peptide by the catalytic chaperone tapasin in the peptide loading complex plays a critical role in antigen presentation and immune recognition. Mechanistic insight has been hampered by the lack of detailed structural information concerning tapasin-MHC-I. We present here crystal structures of human tapasin complexed with the MHC-I molecule HLA-B*4405, and with each of two anti-tapasin antibodies. The tapasin-stabilized peptide-receptive state of HLA-B*4405 is characterized by distortion of the peptide binding groove and destabilization of the ß2-microglobulin interaction, leading to release of peptide. Movements of the membrane proximal Ig-like domains of tapasin, HLA-B*4405, and ß2-microglobulin accompany the transition to a peptide-receptive state. Together this ensemble of crystal structures provides insights into a distinct mechanism of tapasin-mediated peptide exchange.
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1
Base de dados:
MEDLINE
Assunto principal:
Antígenos de Histocompatibilidade Classe I
/
Apresentação de Antígeno
Idioma:
En
Ano de publicação:
2022
Tipo de documento:
Article