Question

Give 2 similarities and 2 differences between RNA synthesis (initiation, elongation, NOT processing) in prokaryotes and eukaryotes

Answer 1

Give 2 similarities and 2 differences between RNA synthesis (initiation, elongation, NOT processing) in prokaryotes and eukaryotes

Transcription is the process of copying the gene's DNA sequence into a RNA molecule catalyzed by enzyme called RNA polymerase. Transcription process initiates with the help of promoter sequence located at the beginning of the gene. The strand which is used by RNA polymerase to produce the complementary strand is called as template strand. The process end with the phase called termination signalled by specific sewuences in the RNA.

Similarities:

The overall process is same in both Pro- & Eu-Karyotes. Both include initiation, elongation and termination. The sequence similarity found between RNA polymerase II of eukaryotes and the prokaryotic RNA polymerases are alpha, Rpb3, and Rpb11.

Another major similarity is the process of elongation. Differences between Pro- & Eu-Karyotes are seen in initiation and termination but the elongation process seems almost same.

Differences:

Prokaryotes have only one RNA polymerase enzyme whereas eukaryotes have three types as RNA polymerases, I, II, and III.

The promoter region in prokaryotes are -10, -35 promoters, and upstream elements and the same in euakaryotes are TATA box, CAAT box, GC box, core promoter downstream and initiator elements.

Transcription occurs simultaneously with translation in prokaryotes but in eukaryotes transcription occursin nucleus and translated in cytoplasm.

Euakryotic transcription followed by post-transcriptional modifications which is not seeen in prokaryotes.

TErmination in prokaryotes are rho-dependent or rho-independent mechanisms whereas in eukaryotes it is mediated by a poly(A) signal and a downstream terminator sequence.