Question

In eukaryotes, what factors or elements (cis and trans) encourage the specific association of RNA polymerase(s) to a specific region of DNA?

A) Promoters and enhancers
B) Introns and exons
C) tRNA and rRNA
D) Okazaki fragments and primase

Answer 1

In eukaryotic transcription, promoters and transcription factors like the basal TFII series are essential for recruiting RNA polymerase II to specific DNA regions for transcription initiation.

Step-by-step explanation:

In eukaryotes, specific association of RNA polymerase to a region of DNA is encouraged by two main elements: promoters and transcription factors. Promoters, such as the TATA box, are DNA sequences that signal the RNA polymerase where to begin transcription. Transcription factors, which include a set of basal transcription factors called TFII, aid in the recruitment of RNA polymerase II to protein-coding genes.

RNA Polymerase I and III also have conserved promoter elements specific to their functions. For instance, RNA polymerase I genes have GC-rich promoter sequences, while RNA polymerase III transcribes genes often with promoters within the genes themselves.

Overall, the eukaryotic transcription initiation complex is formed by the binding of various transcription factors followed by the RNA polymerase at the core promoter region. This complex sequence of events allows for the precise control over gene expression in eukaryotic cells.