Expression, purification and preliminary X-ray crystallographic analysis of Arf1-GDP in complex with dimeric p23 peptide

Arf1 is a member of the Ras superfamily and is involved in COPI vesicle formation. Arf1-GDP can interact with dimeric p23. Here, human Arf1 (residues 18–181) was cloned, expressed and purified in Escherichia coli. For crystallization, Arf1-GDP was mixed with dimeric p23 peptide in a 1:5 molar ratio. Crystals were obtained which diffracted to 2.7 Å resolution. The crystals belonged to space group P6₁22, with unit-cell parameters a = b = 80.6, c = 336.0 Å, α = β = 90, γ = 120°. The asymmetric unit of the crystals contained two molecules, with a Matthews coefficient of 3.2 ų Da⁻¹ and a solvent content of 61.9%.