TFB2M is S-adenosyl-L-methionine-dependent methyltransferase which specifically dimethylates mitochondrial 12S rRNA at the conserved stem loop. This protein is also required for basal transcription of mitochondrial DNA, probably via its interaction with POLRMT and TFAM. TFB2M stimulates transcription independently of the methyltransferase activity. Compared to TFB1M, it activates transcription of mitochondrial DNA more efficiently, while it has less methyltransferase activity. Recombinant human TFB2M protein, fused to His-tag at N-terminus, was expressed in E.coli and purified by using conventional chromatography techniques.