3CVI

How TCR-like antibody recognizes MHC-bound peptide

Summary for 3CVI

• Entry DOI: 10.2210/pdb3cvi/pdb
• Related: 3CVH
• Descriptor: 25-D1.16 Heavy chain, 25-D1.16 Light chain (3 entities in total)
• Functional Keywords: fab, immune system
• Biological source: Mus musculus (mouse); More
• Total number of polymer chains: 2
• Total formula weight: 46636.00

Authors

Mareeva, T.,Martinez-Hackert, E.,Sykulev, Y. (deposition date: 2008-04-18, release date: 2008-09-23, Last modification date: 2024-10-16)

Primary citation

Mareeva, T.,Martinez-Hackert, E.,Sykulev, Y.
How a T cell receptor-like antibody recognizes major histocompatibility complex-bound peptide
J.Biol.Chem., 283:29053-29059, 2008

PubMed Abstract: We determined the crystal structures of the T cell receptor (TCR)-like antibody 25-D1.16 Fab fragment bound to a complex of SIINFEKL peptide from ovalbumin and the H-2K(b) molecule. Remarkably, this antibody directly "reads" the structure of the major histocompatibility complex (MHC)-bound peptide, employing the canonical diagonal binding mode utilized by most TCRs. This is in marked contrast with another TCR-like antibody, Hyb3, bound to melanoma peptide MAGE-A1 in association with HLA-A1 MHC class I. Hyb3 assumes a non-canonical orientation over its cognate peptide-MHC and appears to recognize a conformational epitope in which the MHC contribution is dominant. We conclude that TCR-like antibodies can recognize MHC-bound peptide via two different mechanisms: one is similar to that exploited by the preponderance of TCRs and the other requires a non-canonical antibody orientation over the peptide-MHC complex.

PubMed: 18703505
DOI: 10.1074/jbc.M804996200

Experimental method

X-RAY DIFFRACTION (1.8 Å)