Question

Key polymerases. Compare DNA polymerase and RNA polymerase from E. coli in regard to each of the following

features:
(a) activated precursors,
(b) direction of chain elongation,
(c) conservation of the template, and
(d) need for a primer.

Answer 1

DNA polymerase and RNA polymerase in E. coli both synthesize nucleic acids in the 5' to 3' direction and use a DNA template; however, DNA polymerase requires a primer and uses dNTPs, while RNA polymerase can start without a primer and uses NTPs.

Step-by-step explanation:

Comparison between DNA Polymerase and RNA Polymerase in E. coli

DNA polymerase and RNA polymerase in E. coli have distinct roles in the central dogma of molecular biology. Comparing them in terms of the following features:

Need for a primer: DNA polymerase requires a primer to begin synthesis, while RNA polymerase can initiate RNA synthesis without a primer.

The E. coli RNA polymerase is also notable for its requirement of the sigma factor (σ) for transcription initiation, ensuring specificity in mRNA production. On the other hand, DNA polymerases engage in DNA replication, requiring a primer to add nucleotides and also possessing the ability to correct errors through proofreading functions.