Improved expression, purification and crystallization of a putative N ‐acetyl‐γ‐glutamyl‐phosphate reductase from rice ( Oryza sativa )

N ‐Acetyl‐γ‐glutamyl‐phosphate reductase (AGPR) catalyzes the third step in an eight‐step arginine‐biosynthetic pathway that starts with glutamate. This enzyme converts N ‐acetyl‐γ‐glutamyl phosphate to N ‐acetylglutamate‐γ‐semialdehyde by an NADPH‐dependent reductive dephosphorylation. AGPR from Oryza sativa (OsAGPR) was expressed in Escherichia coli at 291 K as a soluble fusion protein with an upstream thioredoxin‐hexahistidine [Trx‐(His) 6 ] extension. OsAGPR(Ala50–Pro366) was purified and crystals were obtained using the sitting‐drop vapour‐diffusion method at 293 K and diffract X‐rays to at least 1.8 Å resolution. They belong to the hexagonal space group P 6 1 , with unit‐cell parameters a = 86.11, c = 316.3 Å.