Prediction of an rRNA methyltransferase domain in human tumor-specific nucleolar protein P120

Using computer methods for identification of amino acid motifs in sequence databases and multiple alignment, it is shown that human proliferation-associated nucleolar protein P120 contains a putative methyltransferase domain that is conserved in a group of bacterial proteins. It is hypothesized that P120 and the related prokaryotic proteins are rRNA methylases required for division of all types of cells.