Describe what is happening in the following scenario to the repressor, operator,
ID: 198614 • Letter: D
Question
Describe what is happening in the following scenario to the repressor, operator, cAMP production, CAP, CAP binding site, RNA polymerase, and whether or not mRNA gets translated. Be sure to state what effects Lactose and Glucose are having in the appropriate space. (see below)
2. (4 pts) Describe what is happening in the following scenario to the repressor, operator, cAMP production, CAP, CAP binding site, RNA polymerase, and whether or not mRNA gets translated. Be sure to state what effects Lactose and Glucose are having in the appropriate space E. coli with the genotype, l'oZ/F'0. Low levels of lactose and low levels of glucose. Lac operon mutation/phenotypes +Oc7+ epressor gene is normal, mutation in the operator prevents repressor from binding to the operator, (lacZ) B-galactosidase gene is normal Lac I can be expressed as I. Operator can be expressed as 0. Lac Z can be expressed as Z. Etcetera. lacl lacZ acY acA CAP P Repressor & Operator (1 pts): CAMP production and CAP (1 pts) CAP binding site & RNA polymerase (1 pts): mRNA (1 pts):Explanation / Answer
Repressor & Operator: The repressor will be expressed constitutively but will not be able to bind to the operator region due to the mutation in the operator, preventing its binding to the operator. This will result in binding of RNA polymerase to the promoter region of the operon leading to transcription of the downstream genes
cAMP production and CAP: cyclic AMP(cAMP) is a signal molecule whose levels increases under glucose deprivation. Hence cAMP production will be increased under low glucose concentrations. increased cAMP will bind to catabolite activator protein (CAP) allowing it to bind to the CAP binding site.
CAP binding site & RNA polymerase: Increased levels of cAMP will bind to CAP and will enable it to bind CAP binding site which will assist binding of RNA polymerase to promoter region.
mRNA: Failure of Repressor to bind to the operator region(due to mutation in the operator region) and binding of CAP to the CAP binding site(due to low glucose levels) will result in binding of RNA polymerase resulting in transcription of lacZ, lacY and lacA genes.