Overexpression, crystallization and preliminary X-­ray crystallographic analysis of phosphopantetheine adenylyltransferase from Enterococcus faecalis

Phosphopantetheine adenylyltransferase, an essential enzyme in the coenzyme A biosynthetic pathway, catalyzes the reversible transfer of an adenylyl group from ATP to 4'-phosphopantetheine, yielding 3'-dephospho-CoA and pyrophosphate. Enterococcus faecalis PPAT has been overexpressed in Escherichia coli as a fusion with a C-terminal purification tag and crystallized at 297 K using a reservoir solution consisting of 0.1 M sodium HEPES pH 7.5, 0.8 M sodium dihydrogen phosphate and 0.8 M potassium dihydrogen phosphate. X-ray diffraction data were collected to 2.70 Å at 100 K. The crystals belong to the primitive tetragonal space group P4₁ (or P4₃), with unit-cell parameters a = b = 160.81, c = 225.68 Å. Four copies of the hexameric molecule are likely to be present in the asymmetric unit, giving a crystal volume per protein weight (V_M) of 3.08 Å³ Da^-1 and a solvent content of 60.1%.