Purification, crystallization and preliminary X-ray crystallographic analysis of mammalian MSS4-Rab8 GTPase protein complex

Rab GTPases function as ubiquitous key regulators of membrane‐vesicle transport in eukaryotic cells. MSS4 is an evolutionarily conserved protein that binds to exocytotic Rabs and facilitates nucleotide release. The MSS4 protein in complex with nucleotide‐free Rab8 GTPase has been purified and crystallized in a form suitable for structure analysis. The crystals belonged to space group P1, with unit‐cell parameters a = 40.92, b = 49.85, c = 83.48 Å, α = 102.88, β = 97.46, γ = 90.12°. A complete data set has been collected to 2 Å resolution.