The Mechanism of β2m Molecule-Induced Changes in the Peptide Presentation Profile in a Bony Fish.

ABSTRACT: Contemporary antigen presentation knowledge is based on the existence of a single β2m locus, and a classical MHC class I forms a complex with a peptide (i.e., pMHC-I) to trigger CTL immunity. However, two β2m loci have been found in diploid bony fish; the function of the two β2m molecules is unclear. Here, we determined the variant peptide profiles originating from different products of the β2m loci binding to the same MHC-I molecule and further solved the crystal structures of the two pMHC-I molecules (i.e., pCtid-UAA-β2m-2 and pCtid-UAA-β2m-1-II). Of note, in pCtid-UAA-β2m-2, a unique hydrogen bond network formed in the bottom of the peptide-binding groove (PBG) led to α2-helix drift, ultimately leading to structural changes in the PBG. The mechanism of the change in peptide presentation

SUBMITTER: Li Z 

PROVIDER: S-EPMC7240133 | biostudies-literature | 2020 May

REPOSITORIES: biostudies-literature