CD8 (or Cluster of Differentiation 8) is a T-cell co-receptor. CD8 binds to class I MHC protein. CD8 exists as 2 isoforms: α and β. CD8 forms a dimer of CD8α and CD8β. The extracellular domain of CD8 has immunoglobulin variable-like conformation. This domain of CD8α interacts with α3 domain of class I MHC enhancing the binding of the T-cell receptor and the target cell.
3D Structures of CD8
Updated on 18-February-2014
1cd8 – hCD8 extracellular domain – human
CD8α
2hp4 - hCD8 extracellular domain (mutant)
1akj - hCD8 extracellular domain + class I MHC + β-2-microglobulin + HIV reverse transcriptase peptide
3qzw - hCD8 extracellular domain + class I MHC + β-2-microglobulin + NEF peptide
1bqh - mCD8 extracellular domain + class I MHC + β-2-microglobulin + VSV8 peptide - mouse
3dmm - mCD8 extracellular domain + class I MHC + β-2-microglobulin + peptide
1nez - mCD8 extracellular domain + class I MHC + β-2-microglobulin
1q69 - hCD8 residues 209-227 + Lck peptide - NMR
2arj - rCD8 extracellular domain + antibody - rat
2q3a – CD8 extracellular domain – rhesus monkey
CD8α and CD8β
2atp - mCD8 + CD8α CD8β linker
3b9k - mCD8 + antibody
