1XIW

Crystal structure of human CD3-e/d dimer in complex with a UCHT1 single-chain antibody fragment

Summary for 1XIW

• Entry DOI: 10.2210/pdb1xiw/pdb
• Descriptor: T-cell surface glycoprotein CD3 epsilon chain, T-cell surface glycoprotein CD3 delta chain, immunoglobulin light chain variable region, ... (5 entities in total)
• Functional Keywords: cd3-epsilon, cd3-delta, ucht1-scfv, immunoglobulin fold, antibody-antigen complex, membrane protein-immune system complex, membrane protein/immune system
• Biological source: Homo sapiens (human); More
• Cellular location: Cell membrane ; Single-pass type I membrane protein : P07766 P04234
• Total number of polymer chains: 8
• Total formula weight: 93288.08

Authors

Arnett, K.L.,Harrison, S.C.,Wiley, D.C. (deposition date: 2004-09-22, release date: 2004-11-16, Last modification date: 2024-10-30)

Primary citation

Arnett, K.L.,Harrison, S.C.,Wiley, D.C.
Crystal structure of a human CD3-epsilon/delta dimer in complex with a UCHT1 single-chain antibody fragment.
Proc.Natl.Acad.Sci.USA, 101:16268-16273, 2004

PubMed Abstract: The alpha/beta T cell receptor complex transmits signals from MHC/peptide antigens through a set of constitutively associated signaling molecules, including CD3-epsilon/gamma and CD3-epsilon/delta. We report the crystal structure at 1.9-A resolution of a complex between a human CD3-epsilon/delta ectodomain heterodimer and a single-chain fragment of the UCHT1 antibody. CD3-epsilon/delta and CD3-epsilon/gamma share a conserved interface between the Ig-fold ectodomains, with parallel packing of the two G strands. CD3-delta has a more electronegative surface and a more compact Ig fold than CD3-gamma; thus, the two CD3 heterodimers have distinctly different molecular surfaces. The UCHT1 antibody binds near an acidic region of CD3-epsilon opposite the dimer interface, occluding this region from direct interaction with the TCR. This immunodominant epitope may be a uniquely accessible surface in the TCR/CD3 complex, because there is overlap between the binding site of the UCHT1 and OKT3 antibodies. Determination of the CD3-epsilon/delta structure completes the set of TCR/CD3 globular ectodomains and contributes information about exposed CD3 surfaces.

PubMed: 15534202
DOI: 10.1073/pnas.0407359101

Experimental method

X-RAY DIFFRACTION (1.9 Å)