Which statements are correct about lac operator;

I. The site bound by the Lac repressor.

II. The lac operator overlaps the promoter, and so the repressor bound to the operator physically prevents RNA polymerase from binding to the promoter and thus inhibit the RNA synthesis.

III. Have 21-bp sequence with twofold symmetric and is recognized by four subunits of Lac repressor, two binding to each half-site.

IV. CAP binds as a dimer to a site similar in length to that of the lac operator, but different in sequence. This site is located some 60 bp upstream of the start site of transcription.

#Question id: 4487

#Unit 3. Fundamental Processes

Choose correct statements about nucleosome modifiers

#Question id: 4488

#Unit 3. Fundamental Processes

One component of thecomplex bears bromodomains and thus binds to acetylated nucleosomes better than to unacetylated nucleosomes. Thus, a gene bearing acetylated nucleosomes at its promoter will likely have a higher affinity for the transcriptional machinery than one with unacetylated nucleosomes.

#Question id: 4489

#Unit 3. Fundamental Processes

HSP70 gene from Drosophila. This gene, activated by heat shock, is controlled by two activators GAGA binding factor and HSF,In response to heat shock, HSF binds to specific sites at the promoter and recruits a kinase, P-TEFb (positive transcription elongation factor). What is the proper mechanism of pausing and release of Pol II ?

#Question id: 4490

#Unit 3. Fundamental Processes

The human immunodeficiency virus (HIV), which causes AIDS, transcribes its genes from a promoter controlled by P-TEFb (and SEC). Again, polymerase initiates transcription at that promoter, under the control of which activator?

#Question id: 4491

#Unit 3. Fundamental Processes

HIV transcribes its genes from a promoter controlled by P-TEFb, P-TEFb is brought to the stalled polymerase by an RNA-binding protein, not a DNA-bound one. The protein responsible is called

#Question id: 4492

#Unit 3. Fundamental Processes

If an enhancer activates a specific gene 400 kb away, what stops it from activating other genes whose promoters are within that range?