The domain within your query sequence starts at position 119 and ends at position 190; the E-value for the MHCassoc_trimer domain shown below is 6.7e-36.

NMTQDHVMHLLTRSGPLEYPQLKGTFPENLKHLKNSMDGVNWKIFESWMKQWLLFEMSKN
SLEEKKPTEAPP

MHCassoc_trimer

MHCassoc_trimer
PFAM accession number:PF08831
Interpro abstract (IPR011988):

Newly synthesized MHCII proteins associate with a chaperone protein called the invariant chain (Ii) and form a nonameric complex (alpha3beta3Ii3) in the endoplasmic reticulum [(PUBMED:1956401)]. Ii plays a critical role in the assembly of the MHC, as well as in MHC II antigen processing by stabilising peptide-free class II alpha/beta heterodimers in a complex soon after their synthesis and directing transport of the complex from the endoplasmic reticulum to compartments where peptide loading of class II takes place [(PUBMED:16337363)]. In antigen-presenting cells (APCs), loading of MHC II molecules with peptides is regulated by Ii, which blocks MHC II antigen-binding sites in pre-endosomal compartments [(PUBMED:16181341)]. Several molecules then act upon MHC II molecules in endosomes to facilitate peptide loading: Ii-degrading proteases, the peptide exchange factor, human leukocyte antigen-DM (HLA-DM), and its modulator, HLA-DO (DO).

Ii first assembles into a trimer and then associates with three class II alpha/beta MHC heterodimers. This entry represents the trimerisation domain of Ii. Its structure has been determined by NMR [(PUBMED:9843486)].

GO process:antigen processing and presentation (GO:0019882)
GO component:integral component of membrane (GO:0016021)
GO function:MHC class II protein binding (GO:0042289)

This is a PFAM domain. For full annotation and more information, please see the PFAM entry MHCassoc_trimer