Why is ribosomal protein L11 of Escherichia coli methylated

Escherichia coli spends a significant amount of energy to synthesize one (or more than one) enzyme which further spends energy in transferring nine methyl groups from S-adenosyl-methionine (SAM) to ribosomal protein L11. Our current opinion is that spending this energy is meaningless, because an E. coli mutant (prmA1) completely lacks methylation of L11 while exhibiting no detectable deleterious phenotype (Colson and Smith, 1977). We summarize here some of the efforts made, using mutant prmA1, to unveil a function of L11 methylation. In addition we present preliminary results of a cloning project to further characterize the methylating enzyme(s) of L11.