1
Q
sacB
A
levansucrase gene from B. subtilis that will produce
a toxic compound to cells grown on sucrose plates–if you break it, cell will live
2
Q
rpsL
A
encodes a ribosomal subunit that is sensitive to streptomycin
3
Q
URA3
A
encodes a step of uracil synthesis pathway that will convert 5-fluoro-orotic acid into a toxic product
4
Q
HSVtk
A
herpes virus thymidine kinase – converts ganciclovir into a toxic compound (useful in plant and animal systems)
