Expression, purification, crystallization and preliminary diffraction studies of the mammalian DAG kinase homologue YegS from Escherichia coli

yegS is a gene encoding a 32 kDa cytosolic protein with unknown function but with strong sequence homology to a family of structurally uncharacterized eukaryotic non- protein kinases: diacylglycerol kinases, sphingosine kinases and ceramide kinases. Here, the overexpression, crystallization and preliminary diffraction analysis of Escherichia coli YegS are reported. The crystals belong to space group P2(1), with unit-cell parameters a = 42.4, b = 166.1, c = 48.5 angstrom, beta = 96.97 degrees. The presence of a dimer in the asymmetric unit was estimated to give a Matthews coefficient (V-M) of 2.5 angstrom(3) Da (-1) and a solvent content of 50.8%(v/ v). Single-wavelength diffraction data were collected to a resolution of 1.9 angstrom using synchrotron radiation.