I need help with this problem please explain thanks... You are interested in exa
ID: 79179 • Letter: I
Question
I need help with this problem please explain thanks...
You are interested in examining the regulation of the gene that encodes a enzyme, Tre-ase, important in metabloizing trehalose into glucose in bacteria. Trehalose is a disaccharide formed of two glucose units. It is known that two DNA binding proteins, TreA and TreB, are important for binding to the promoter of the Tre-ase gene and are involved in regulating the transcription of the Tre-ease gene: TreA binds to the "A" site in the promoter region and TreB binds to the "B" site. You make mutations in the TreA and TreB genes to create cells lacking theses genes, observe what happens to transcription of the Tre-ease gene, and obtain the results in the table below.
A. What is the role for TreA in controlling a Tre-ease expression? explain.
B. What is the role for TreB in controlling Tre-as expression? explain.
C. from these data what do you predict will happen to the Tre-ase transcription compared with that in normal cells in the presence of you were to create a version of the TreA protein that will constitutely bind to the "A" site in the Tre-ase promoter?
Transcription of Tre-ase in different media Glucose on Trehalose only Trehalowe normal Cells lacking TreA Cells lacking TreB off Cells lacking both TreA TreB offExplanation / Answer
A. Role of TreA:- TreA acts as a repressor protein. The cells lacking TreA show constitutive expression of the trehalose operon (as would be in normal cells). The transcription is ON in absence of TreA, when trehalose is present (only trehalose or trehalose with glucose). Presence of trehalose along with glucose also switch on the transcription confirms that TreA is a repressor.
B. Role of B:- TreB acts as an activator protein. When TreB is absent, transcription is switched off. No expression of trehalose operon, as lack of activation due to absence of TreB activator protein.
C. The given data suggests that TreA is a repressor protein, therefore if version of TreA protein constitutely binds to A site, Transcription of trehalose operon will be switched off. Transcription will not occur even in presence of trehalose.