Expression, purification, crystallization and preliminary X-ray diffraction analysis of the C-terminal NHL domain of human TRIM2

The tripartite motif-containing protein 2 (TRIM2) functions as an E3 ubiquitin ligase. Loss of function of TRIM2 has been shown to result in early-onset axonal neuropathy. As a member of the TRIM–NHL family of proteins, TRIM2 has a conserved modular architecture that includes N-terminal RING finger and B-box domains, a middle coiled-coil domain and a C-terminal NHL domain. To characterize the functional role of its NHL domain from the perspective of structural biology, a truncation of human TRIM2 (residues 465–744) was expressed, purified and crystallized. Rod-shaped crystals were obtained that diffracted X-rays to 1.7 Å resolution. The crystals belonged to space group P2₁, with unit-cell parameters a = 43.6, b = 76.4, c = 107.4 Å, α = 90.0, β = 94.0, γ = 90.0°. A Matthews coefficient of 1.97 ų Da⁻¹, corresponding to a solvent content of 37.6%, indicated the presence of three molecules per asymmetric unit, which was further confirmed by the phasing solution from molecular replacement.