Single crystals of the focal adhesion kinase FAT domain were used for data collection. A single crystal diffracted to 1.99 Å and was indexed in a primitive orthorhombic space group, with unit-cell parameters a = 48.246, b = 50.289, c = 49.532 Å. The unit cell belonged to space group P212121. The Matthews coefficient was computed using the Matthews Probability Calculator as 2.27 Å3 Da−1, indicating the presence of a single molecule in the asymmetric unit. The solvent content was predicted to be 46% with a unit-cell volume of 120 177.2 Å3 and a molecular weight of 14 244.71 Da (Table 1).
Data-collection and reduction statistics
The structure of human focal adhesion kinase FAT domain has previously been solved in a C
-centered orthorhombic space group (C
). The original model used for phasing by molecular replacement was PDB entry 1k04
(Arold et al.
). Molecular-replacement methods yielded the single predicted molecule in the asymmetric unit. As shown in Fig. 1, the 15-residue loop region (residues 906–920) of the FAK FAT domain was omitted from the protein in this experiment. It could therefore be suggested that this N-terminal loop region of the C
FAK FAT domain determined the crystal space group, as this region could sterically prevent the tight packing seen in the primitive orthorhombic crystal structure. Another human FAK FAT domain (PDB code 1k05
; Arold et al.
) also crystallized in space group C
with this N-terminal loop. It should be noted that the mouse FAK FAT domain, which is 98% identical to the human homolog, crystallized in space group C
2 in the absence of this loop region (Fig. 2; Hayashi et al.
Figure 1 (a) Primitive orthorhombic focal adhesion kinase FAT domain (unrefined) from this experiment; (b) C-centered orthorhombic FAK FAT domain (PDB code 1k04) containing the N-terminal loop region. Images created with PyMOL (DeLano, 2002 ).
Figure 2 Crystal packing of (a) the human FAK FAT domain in a primitive orthorhombic space group (P212121) and (b) the mouse FAK FAT domain in a C-centered monoclinic space group (C2; PDB code 1k40). Images created with PyMOL.