Crystallization and preliminary X-ray data collection of the L27(PATJ)-(L27N,L27C)(Pals1)-L27(MALS) tripartite complex.

The L27 (LIN-2/LIN-7) domain is a protein-protein interaction module capable of assembling proteins into biologically important complexes. Pals1 contains two L27 domains: the first, L27N, interacts with PATJ, and the second, L27C, interacts with MALS, forming a tripartite complex that plays a crucial role in the establishment and maintenance of cell polarity. To provide a better understanding of the mechanism of assembly of this tripartite complex, four different L27(PATJ)-(L27N,L27C)(Pals1)-L27(MALS) constructs were cloned, expressed, purified and crystallized. Crystals of tripartite complex 1 of L27(PATJ)-(L27N,L27C)(Pals1)-L27(MALS) diffracted to 2.05 Å resolution. These crystals belonged to either space group P6(1)22 or P6(5)22, with unit-cell parameters a = b = 145.2, c = 202.5 Å. Assuming the presence of four molecules in the asymmetric unit, a Matthews coefficient of 2.69 Å(3) Da(-1) was calculated, corresponding to a solvent content of 54.25%.