Production, crystallization and preliminary X-ray analysis of CTP:inositol-1-phosphate cytidylyltransferase from Archaeoglobus fulgidus.

Archaeoglobus fulgidus, a hyperthermophilic archaeon, accumulates di-myo-inositol phosphate (DIP) in response to heat stress. Recently, the pathway for biosynthesis of DIP has been elucidated in this organism and involves a bifunctional enzyme that contains two domains: CTP:inositol-1-phosphate cytidylyltransferase (IPCT) as a soluble domain and di-myo-inositol-1,3'-phosphate-1-phosphate synthase (DIPPS) as a membrane domain. Here, the expression, purification, crystallization and preliminary X-ray diffraction analysis of the IPCT domain from A. fulgidus in the apo form are reported. The crystals diffracted to 2.4 Å resolution using a synchrotron source and belonged to the orthorhombic space group P2(1)2(1)2, with unit-cell parameters a = 154.7, b = 83.9, c = 127.7 Å.