Purification, crystallization and preliminary crystallographic analysis of human dihydrodipicolinate synthase-like protein (DHDPSL)

Human dihydrodipicolinate synthase-like protein (DHDPSL) is a gene product of unknown function. It is homologous to bacterial pyruvate-dependent aldolases such as dihydrodipicolinate synthase (DHDPS), which functions in lysine biosynthesis. However, it cannot have this function and instead is implicated in a genetic disorder that leads to excessive production of oxalate and kidney-stone formation. In order to better understand its function, DHDPSL was expressed as an MBP-fusion protein and crystallized using an in situ proteolysis protocol. Two crystal forms were obtained, both of which diffracted X-rays to approximately 2.0 Å resolution. One of these, belonging to space group P6₂22 or P6₄22 with unit-cell parameters a = b = 142.9, c = 109.8 Å, α = β = 90, γ = 120°, was highly reproducible and suitable for structure determination by X-ray crystallography.