Promiscuous Ribozymes and Their Proposed Role in Prebiotic Evolution

Area of Science:

• Biochemistry
• Origin of Life Studies
• Enzyme Evolution

Background:

• Enzyme promiscuity, the ability to catalyze side reactions, is crucial for evolving new biochemical functions.
• Speculation suggests early ribozymes were highly promiscuous, later evolving into specialized enzymes with higher activity and specificity.

Purpose of the Study:

• To review concepts of enzyme promiscuity in ribozymes.
• To examine cases of highly promiscuous ribozymes.
• To assess if de novo ribozymes are inherently more promiscuous than evolved enzymes.

Main Methods:

• Literature review of promiscuity concepts.
• Analysis of existing studies on highly promiscuous ribozymes.
• Comparative assessment of promiscuity in de novo vs. evolved ribozymes and protein enzymes.

Main Results:

• De novo ribozymes generally exhibit promiscuity.
• De novo ribozymes are not quantitatively more promiscuous than highly evolved or active sequences.
• Promiscuity's value is contingent on selective pressures, even in prebiotic evolution.

Conclusions:

• While de novo ribozymes are generally promiscuous, they do not surpass evolved enzymes in this trait.
• The significance of promiscuity as a trait varies with evolutionary and selective contexts.
• Understanding ribozyme promiscuity offers insights into the origin and evolution of biochemical diversity.