HG2A_HUMAN » HLA class II histocompatibility antigen gamma chain

HG2A_HUMAN » HLA class II histocompatibility antigen gamma chain
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Topology in Plasma membrane
Topologyextracellular side
cytoplasmic side
HG2A_HUMAN » HLA class II histocompatibility antigen gamma chain » HLA-DR antigens-associated invariant chain;Ia antigen-associated invariant chain;Ii; p33;
Hydrophobic Thickness 28.4 ± 3.3 Å
Tilt Angle 30 ± 0°
ΔGtransfer -18.4 kcal/mol
ΔGfold -12.1 kcal/mol
Links UniProtKB, Pfam, Interpro, iHOP, STRING, HGNC, Reactome
Topology In
TM Segments 48-69 (48-75)
Pathways

Antigen processing and presentation (KEGG)

Herpes simplex infection (KEGG)

Immune System (Reactome)

Tuberculosis (KEGG)

PDB 1l3h (210-274), 1iie (A/B/C=134-208), 4ah2 (B=106-120), 3qxd (C/F=103-117), 3qxa (C/F=103-117), 3pgd (C/F=106-120), 3pgc (C/F=106-120), 3pdo (C=102-120), 1a6a (C=103-117), 4aen (C=106-120), 1muj (C=97-121), 1icf (I/J=210-274)
OPM none
Complexes

HG2A:DRA:2B11_HUMAN

2B13:HG2A:DRA_HUMAN

HG2A:HG2A_HUMAN

Interactions

2B11, Complex: HG2A:DRA:2B11, PDBID: 3PDO

2B13, Complex: 2B13:HG2A:DRA, PDBID: 1A6A

A4, Complex: HG2A:A4, PubMed

CD1D, Complex: CD1D:HG2A, PubMed

CD44, Complex: HG2A:CD44, PubMed

DMA, Complex: DMA:HG2A, PubMed

DMB, Complex: DMB:HG2A, PubMed

DPA1, Complex: HG2A:DPA1, PubMed

DPB1, Complex: HG2A:DPB1, PubMed

DQA1, Complex: DQA1:HG2A, PubMed

DQB1, Complex: DQB1:HG2A, PubMed

DRA, Complex: HG2A:DRA, PubMed

HG2A, Complex: Ectoplasmic trimerization domain of HG2A, PDBID: 1IIE

Domains

AA: 17-129, PDBID: 1A6A, Subunit C, Seq Identity:100%, CLIP, MHC2 interacting

AA: 136-204, PDBID: 1IIE, Subunit A, Seq Identity:100%, Class II MHC-associated invariant chain trimerisation domain

AA: 208-271, PDBID: 1ICF, Subunit I, Seq Identity:100%, Thyroglobulin type-1 repeat

UniProt annotation for HG2A_HUMAN » HLA class II histocompatibility antigen gamma chain
FUNCTION: Plays a critical role in MHC class II antigen processing by stabilizing 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 the endosomal/lysosomal system where the antigen processing and binding of antigenic peptides to MHC class II takes place. Serves as cell surface receptor for the cytokine MIF.

SUBUNIT: Homotrimer. In the endoplasmic reticulum (ER) it forms a heterononameric MHC II-Ii complex: 3 MHC class II molecules (heterodimers of an alpha and a beta subunit) bind to the CD74 homotrimer (also known as invariant chain or HLA class II histocompatibility antigen gamma chain). In the endosomal/lysosomal system, the CD74 component undergoes sequential degradation by various proteases, including CTSS and CTSL, leaving a small fragment termed CLIP (class-II-associated invariant chain peptide) attached to the MHC class II molecule (alpha-beta-CLIP complex). This processed complex interacts with HLA_DM and HLA_DO heterodimers in order to release CLIP and facilitate the binding of antigenic peptides to the MHC class II molecules.

DISEASE: Note=A chromosomal aberration involving CD74 is found in a non-small cell lung tumor. Results in the formation of a CD74- ROS1 chimeric protein.

UniProt features for HG2A_HUMAN » HLA class II histocompatibility antigen gamma chain
CHAIN 1 296 HLA class II histocompatibility antigen gamma chain.
DOMAIN 210 271 Thyroglobulin type-1.
REGION 103 117 CLIP.
SITE 208 209 Breakpoint for translocation to form a CD74-ROS1 fusion protein.
DISULFID 213 232
DISULFID 243 250
DISULFID 252 271
Amino Acid Sequence for HG2A_HUMAN » HLA class II histocompatibility antigen gamma chain
MHRRRSRSCR EDQKPVMDDQ RDLISNNEQL PMLGRRPGAP ESKCSRGALY TGFSILVTLL LAGQATTAYF LYQQQGRLDK LTVTSQNLQL ENLRMKLPKP PKPVSKMRMA TPLLMQALPM GALPQGPMQN ATKYGNMTED HVMHLLQNAD PLKVYPPLKG SFPENLRHLK NTMETIDWKV FESWMHHWLL FEMSRHSLEQ KPTDAPPKVL TKCQEEVSHI PAVHPGSFRP KCDENGNYLP LQCYGSIGYC WCVFPNGTEV PNTRSRGHHN CSESLELEDP SSGLGVTKQD LGPVPM