Crystallization and preliminary X-ray analysis of the complex between human CTLA-4 and B7-2

CTLA-4 is a dimeric T-cell surface receptor responsible for transducing signals that down-regulate activated T cells upon binding B7 ligands. The disulfide-linked homodimer of the extracellular segment of human CTLA-4 and the receptor-binding domain of human B7-2 were purified and cocrystallized. Diffraction from these crystals is consistent with the monoclinic space group P2(1) (unit-cell parameters a = 47.85, b = 54.56, c = 103.09 A, beta = 91.63); native data have been collected to 3.2 A resolution.