Overexpression, crystallization and preliminary X-ray crystallographic analysis of dihydrofolate reductase from bacteriophage T4

Abstract

Dihydrofolate reductase (DHFR) from bacteriophage T4 is a homodimer consisting of 193-residue subunits. It has been crystallized in the presence of the cofactor (NADPH) and an inhibitor (aminopterin) at 296 K using sodium chloride as precipitant. The crystals are tetragonal, belonging to the space group P4 1 22 (or P4 3 22), with unit-cell parameters a = b = 61.14, c = 123.23 A Ê under cryogenic conditions. The asymmetric unit contains a single subunit, with a corresponding V m of 2.65 A Ê 3 Da À1 and a solvent content of 53.6%. Native data have been collected from a crystal to 1.9 A Ê resolution using synchrotron X-rays.