TFB1M belongs to the methyltransferase superfamily. TFB1M is a dimethyltransferase that methylates mitochondrial 12S rRNA at the conserved stem loop. This protein also is part of the basal mitochondrial transcription complex and is necessary for mitochondrial gene expression. TFB1M stimulates transcription independently of the methyltransferase activity. Recombinant human TFB1M protein, fused to His-tag at N-terminus, was expressed in E.coli and purified by using conventional chromatography.