Now that the MaGellin assay was validated for non-specific methylases, we were ready to test site-specific methylases. Our MaGellin assay is ideal for high-throughput construction and testing of these enzymes. Site-specific methylases are fusion proteins, a DNA binding domain linked to a methylase by a serine glycine chain. They can direct DNA methylation to specific sequences, likely promoter regions for use as a transcriptional silencer. We used the prokaryotic methylase M.SssI for all of our studies (BBa_K1128000).
We wanted to first recapitulate published results with a zinc finger binding domain, and then characterize our two novel site-specific methylases: using the TALE and CRISPR/Cas binding domains.
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