1. You have an E. coli lac operon on an Fplasmid. Everything about the operon is wild type. Now you create a hybrid lac-trp operon by inserting the trp leader region (without the trp promoter) in between the laco and lacZ. This hybrid lac-trp operon is on the F' plasmid in Strain Y which is Nal (sensitive to the antibiotic nalidixic acid). a. (4 pts) Draw the structure of this hybrid operon. b. (12 pts) Strain X of E. coli has the lac operon deleted from it and is Nal' (mutation carried on the chromosome that confers resistant to nalidixic acid). Strain X has no other plasmids in it. You want to move your F' plasmid containing the lac-trp hybrid into Strain X via conjugation. You mix Strain X and Strain Y and let the mixture sit quietly in the incubator for 1 hr and then plate the mixture on minimal medium agar. You must decide which of the following medium supplements will be added to the medium to ensure that you select for exconjugants and counterselect againt both the donor and recipient strains. For each of the following supplements, state whether or not it will be included in your agar medium and then discuss why you made that choice. In your answer, you need to explain how the supplement will help in either the selection of exconjugants or counterselection against donor (Strain Y) and recipient (Strain X). You also need to think about and discuss how each supplement might affect regulation of your hybrid operon. i. Glucose ii. Lactose iii. Tryptophan iv. Naladixic acid PLEASE explain very well/ thought out answers and answer all parts !! 1. You have an E. coli lac operon on an Fplasmid. Everything about the operon is wild type. Now you create a hybrid lac-trp operon by inserting the trp leader region (without the trp promoter) in between the laco and lacZ. This hybrid lac-trp operon is on the F' plasmid in Strain Y which is Nal (sensitive to the antibiotic nalidixic acid). a. (4 pts) Draw the structure of this hybrid operon. b. (12 pts) Strain X of E. coli has the lac operon deleted from it and is Nal' (mutation carried on the chromosome that confers resistant to nalidixic acid). Strain X has no other plasmids in it. You want to move your F' plasmid containing the lac-trp hybrid into Strain X via conjugation. You mix Strain X and Strain Y and let the mixture sit quietly in the incubator for 1 hr and then plate the mixture on minimal medium agar. You must decide which of the following medium supplements will be added to the medium to ensure that you select for exconjugants and counterselect againt both the donor and recipient strains. For each of the following supplements, state whether or not it will be included in your agar medium and then discuss why you made that choice. In your answer, you need to explain how the supplement will help in either the selection of exconjugants or counterselection against donor (Strain Y) and recipient (Strain X). You also need to think about and discuss how each supplement might affect regulation of your hybrid operon. i. Glucose ii. Lactose iii. Tryptophan iv. Naladixic acid PLEASE explain very well/ thought out answers and answer all parts
