Crystallization and preliminary X-ray analysis of CTLA-4 (CD152) membrane-external domain

CTLA-4 (CD152) is involved in T-lymphocyte co-stimulatory pathways modulating both humoral and cellular immune response. The membrane-external domain has been prepared and crystallized. The unit-cell parameters are a = b = 43, c = 143 A with the symmetry of space group P3121 or its enantiomer and the crystals diffract to 2.7 A resolution at synchrotron beamlines.