Question

Enhancers bind to DNA upstream of the promoter region and allow ____ to begin to catalyze mRNA synthesis.

Answer 1

Enhancers bind to DNA upstream of the promoter region and allow _______
to begin to catalyze mRNA synthesis.

ans: RNA polymerase - II

• Many eukaryotic genes possess enhancer sequences, which can be found at considerable distances from the genes they affect.
• Enhancer sequences control gene activation by binding with activator proteins and altering the 3-D structure of the DNA to help "attract" RNA pol II, thus regulating transcription.
• The process of transcription begins when RNA polymerase (RNA pol) attaches to the template DNA strand and begins to catalyze production of complementary RNA.
• Three different types of RNA polymerase exist in eukaryotic cells, whereas bacteria have only one.
• In eukaryotes, RNA pol I transcribes the genes that encode most of the ribosomal RNAs (rRNAs), and RNA pol III transcribes the genes for one small rRNA, plus the transfer RNAs that play a key role in the translation process, as well as other small regulatory RNA molecules.
• Thus, it is RNA pol II that transcribes the messenger RNAs, which serve as the templates for production of protein molecules.