4. How does DNA mismatch repair (MMR) machinery in bacteria determine which base in a mismatched base pair needs to be corrected?

5. David would like to design an expression construct that allows expressions of green fluorescent protein (GFP) and coronavirus spike (S) protein from one single RNA in 293T cells. Please draw a map of this construct and provide the rationale of the construct design, e.g., explain the function of each critical component on this map.