The cluster binding sequence from another ribosomal RNA 5-methyluridine methyltransferase, RumB, is also shown. Absolutely conserved residues are in solid blocks with white letters, and residues within hollow blocks vary at only one sequence in this subset. The residue positions indicated on top are for E. coli RumA. This figure was generated by ESPript (53). The two-letter species abbreviations used are: Ec, E. coli; Pf, Pyrococcus furiosus; Sp, Schizosaccharomyces pombe; Os, Oryza sativa; and Ce, Corynebacterium efficiens.