BUD31 is a nuclear protein that belongs to the BUD31 (G10) family. It contains a putative nuclear translocation sequence, an N-terminal acidic domain and a cysteine-rich C-terminal domain containing a putative Zinc-finger structure. The structure of BUD31 suggests that it may be a nuclear regulator of transcription. Recombinant human BUD31 protein, fused to His-tag at N-terminus, was expressed in E.coli and purified by using conventional chromatography techniques.