1ncn
From Proteopedia
(New page: 200px<br /> <applet load="1ncn" size="450" color="white" frame="true" align="right" spinBox="true" caption="1ncn, resolution 2.70Å" /> '''the receptor-bindin...) |
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| - | [[Image:1ncn.gif|left|200px]]<br /> | + | [[Image:1ncn.gif|left|200px]]<br /><applet load="1ncn" size="350" color="white" frame="true" align="right" spinBox="true" |
| - | <applet load="1ncn" size=" | + | |
caption="1ncn, resolution 2.70Å" /> | caption="1ncn, resolution 2.70Å" /> | ||
'''the receptor-binding domain of human B7-2'''<br /> | '''the receptor-binding domain of human B7-2'''<br /> | ||
==Overview== | ==Overview== | ||
| - | B7-1 and B7-2 are homologous costimulatory ligands expressed on the | + | 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. |
==About this Structure== | ==About this Structure== | ||
| - | 1NCN is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http:// | + | 1NCN is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1NCN OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Homo sapiens]] | [[Category: Homo sapiens]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Almo, S | + | [[Category: Almo, S C.]] |
| - | [[Category: Nathenson, S | + | [[Category: Nathenson, S G.]] |
| - | [[Category: Schwartz, J | + | [[Category: Schwartz, J D.]] |
[[Category: Zhang, X.]] | [[Category: Zhang, X.]] | ||
[[Category: beta strands]] | [[Category: beta strands]] | ||
[[Category: ig v]] | [[Category: ig v]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:04:39 2008'' |
Revision as of 12:04, 21 February 2008
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the receptor-binding domain of human B7-2
Overview
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.
About this Structure
1NCN is a Single protein structure of sequence from Homo sapiens. Full crystallographic information is available from OCA.
Reference
Crystal structure of the receptor-binding domain of human B7-2: insights into organization and signaling., Zhang X, Schwartz JC, Almo SC, Nathenson SG, Proc Natl Acad Sci U S A. 2003 Mar 4;100(5):2586-91. Epub 2003 Feb 26. PMID:12606712
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