1NCN

the receptor-binding domain of human B7-2

Summary for 1NCN

• Entry DOI: 10.2210/pdb1ncn/pdb
• Related: 1I85
• Descriptor: T lymphocyte activation antigen CD86 (1 entity in total)
• Functional Keywords: ig v, beta strands, immune system
• Biological source: Homo sapiens (human)
• Cellular location: Cell membrane; Single-pass type I membrane protein: P42081
• Total number of polymer chains: 2
• Total formula weight: 25699.26

Authors

Zhang, X.,Schwartz, J.D.,Almo, S.C.,Nathenson, S.G. (deposition date: 2002-12-05, release date: 2003-03-11, Last modification date: 2024-10-30)

Primary citation

Zhang, X.,Schwartz, J.D.,Almo, S.C.,Nathenson, S.G.
Crystal Structure of the Receptor-Binding Domain of Human B7-2: Insights into Organization and Signaling
Proc.Natl.Acad.Sci.USA, 100:2586-2591, 2003

PubMed Abstract: B7-1 and B7-2 are homologous costimulatory ligands expressed on the surfaces of antigen-presenting cells. Their interactions with CD28/CTLA-4 receptors expressed on T cell surfaces are crucial for the proper regulation of T cell activity. B7-1 and B7-2 display distinct roles in immune regulation, although they are usually considered to have redundant functions. Here, we report the crystal structure of the receptor-binding (Ig V-type) domain of human B7-2 at 2.7-A resolution. Structures of unliganded and liganded B7-1 and B7-2 suggest a physical-chemical basis for the observed functional similarities and differences between these two costimulatory ligands. Of particular note, whereas the majority of the residues mediating B7-1 dimerization are hydrophobic, the B7-2 dimer observed in the B7-2/CTLA-4 complex displays a very hydrophilic dimer interface. These differences provide a mechanism for preventing the formation of B7-1/B7-2 heterodimers. The divergence at the putative dimer interface is also consistent with the lower tendency of B7-2 to dimerize, as shown by the monomeric state of unliganded B7-2 both in solution and crystalline form, and may result in detailed differences in signaling mechanisms associated with B7-1 and B7-2.

PubMed: 12606712
DOI: 10.1073/pnas.252771499

Experimental method

X-RAY DIFFRACTION (2.7 Å)