2aw2

Publication Abstract from PubMed

Five CD28-like proteins exert positive or negative effects on immune cells. Only four of these five receptors interact with members of the B7 family. The exception is BTLA (B and T lymphocyte attenuator), which instead interacts with the tumor necrosis factor receptor superfamily member HVEM (herpes virus entry mediator). To better understand this interaction, we determined the 2.8-A crystal structure of the BTLA-HVEM complex. This structure shows that BTLA binds the N-terminal cysteine-rich domain of HVEM and employs a unique binding surface compared with other CD28-like receptors. Moreover, the structure shows that BTLA recognizes the same surface on HVEM as gD (herpes virus glycoprotein D) and utilizes a similar binding motif. Light scattering analysis demonstrates that the extracellular domain of BTLA is monomeric and that BTLA and HVEM form a 1:1 complex. Alanine-scanning mutagenesis of HVEM was used to further define critical binding residues. Finally, BTLA adopts an immunoglobulin I-set fold. Despite structural similarities to other CD28-like members, BTLA represents a unique co-receptor.

Attenuating lymphocyte activity: the crystal structure of the BTLA-HVEM complex.,Compaan DM, Gonzalez LC, Tom I, Loyet KM, Eaton D, Hymowitz SG J Biol Chem. 2005 Nov 25;280(47):39553-61. Epub 2005 Sep 16. PMID:16169851^[3]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.