On the early evolution of RNA polymerase

Area of Science:

• Molecular Evolution
• Biochemistry
• Genetics

Background:

• Evidence suggests RNA predated DNA as the primary genetic material.
• RNA polymerase is hypothesized as one of the earliest proteins.
• The beta' subunit of DNA-dependent RNA polymerase may retain ancient features.

Purpose of the Study:

• To review evidence for RNA preceding DNA.
• To hypothesize the evolutionary origins of RNA polymerase.
• To examine the phylogenetic significance of the beta' subunit.

Main Methods:

• Review of existing scientific literature and evidence.
• Comparative analysis of RNA polymerase subunits across different life forms.
• Phylogenetic analysis of conserved protein domains.

Main Results:

• The eubacterial beta' subunit of RNA polymerase shows homology to ancient enzymes.
• Evidence supports a potential replicase function for this ancient polypeptide.
• Certain features of the E. coli transcriptional apparatus appear to be recent evolutionary developments.

Conclusions:

• The beta' subunit serves as a molecular fossil, offering insights into early life.
• Studying this subunit aids in understanding evolutionary relationships among major cellular domains and viruses.
• This research highlights the deep evolutionary history embedded within fundamental cellular machinery.