https://pages.htgaa.org/2026b/rachel-lee/week-02-hw-dna-design/index.htmlPart 1 — What am I expressing? My product is DNA, so there’s no protein that “makes” it — the cell’s own replication machinery does. The plasmid therefore carries two different things: A protein: M.SssI, a CpG DNA methyltransferase.1 It adds a methyl group to the cytosine in every CG pair. Why: vertebrate DNA is CpG-methylated, bacterial DNA isn’t, and unmethylated CpG is read by the immune receptor TLR9 as a danger signal.23 This was the biggest risk identified in HW1. Methylating the DNA as it’s made makes it look vertebrate-like. The enzyme is a process aid — it gets thrown away during purification. The product: an AT-rich array of defined-length DNA units. A non-coding part whose sequence is the deliverable. Neat detail: the plasmid is both the vector and the product — 49.6% of its mass is product.Hugoen