RNA m5C methyltransferases are a group of enzymes that catalyze the transfer of a methyl group to a cytosine nucleotide of RNA. Only two of these enzymes have been well characterized: Fmu from E. coli and Trm4p from S. cerevisiae. YNLO22c is one of three ORFs identified in S. cerevisiae that have homology with both known and putative RNA m5C methyltransferases, but its encoded protein, YNLO22p, has not been confirmed to have enzyme activity. Verifying that YNLO22c encodes an RNA m5C methyltransferase will require adequate amounts of soluble YNLO22p for enzyme assays. A bacterial expression plasmid for YNLO22c was developed, but the result was insoluble protein. Therefore, several methods known to improve protein solubility were tested to develop a system in which a sufficient amount of soluble YNLO22p could be produced. Results of this study found that coexpression of YNLO22c with chaperone proteins can provide sufficient quantities of soluble YNLO22p. / Department of Biology