IUCr journals

De novo sulfur SAD phasing of the lysosomal 66.3 kDa protein from mouse

Acta Cryst. (2009). D65, 220-228 [doi.org/10.1107/S0907444908041814]

[Difference map] Anomalous difference map contoured at 4.0σ (dark green). One peak represents the Xe atom, which is indicated as a blue sphere. For orientation, the Cα trace of the refined 66.3 kDa protein structure (PDB code 3FBX) is shown with cisteine and methionine side chains in stick mode and S atoms highlighted as yellow spheres. The two disulfide bonds are marked with black arrows.
The structure of the lysosomal 66.3 kDa protein from mouse has been determined by means of sulfur SAD (S-SAD) using crystals belonging to space group C2. Thus, this is one of the largest protein structures solved by S-SAD phasing so far and expands the limited number of successful S-SAD phase determinations in monoclinic space groups. The data exhibit an Ranom/Rp.i.m. ratio of only 1.1. A single xenon atom caught in a hydrophobic pocket during a xenon soak was not required for successful phasing.

K. Lakomek, A. Dickmanns, U. Mueller, K. Kollmann, F. Deuschl, A. Berndt, T. Lübke and R. Ficner