Crystallization and initial crystal characterization of the C-terminal phosphoglycerate mutase homology domain of Sts-1.

Sts-1 is a multidomain protein that plays an important role in T-cell signaling. Sts-1 contains a ubiquitin-association (UBA) domain at the N-terminus, followed by an Src homology-3 (SH3) domain and a C-terminal domain that shares sequence homology to phosphoglycerate mutases (PGMs). The C-terminal domain of Sts-1, Sts-1(PGM), crystallizes in space group C2 with two different crystal forms. The first crystal form contains two or three Sts-1PGM molecules in the asymmetric unit and diffracts to 1.82 A resolution, with unit-cell parameters a = 116.2, b = 74.3, c = 100.1 A, alpha = gamma = 90, beta = 101.5 degrees. The second crystal form contains four or six Sts-1(PGM) molecules in the asymmetric unit, with unit-cell parameters a = 214.9, b = 75.1, c = 116.4 A, alpha = gamma = 90, beta = 111.6 degrees. Greater than 95% complete native and SeMet data sets have been collected and structure determination using the multiple anomalous dispersion (MAD) technique is ongoing.