With the advent of next-generation sequencing technologies, the genomic sequences for an ever-expanding number of organisms have been decoded, providing immense databases of protein amino acid sequences and DNA and RNA nucleotide sequences. These databases are allowing comparisons across thousands of species, enabling the identification of those that have undergone significant molecular evolution in specific proteins or RNA molecules. In the 21st century, RNA biology has gained major attention with the discovery of functional non-coding RNAs and regulatory systems including CRISPR. These advances have clarified with high resolution the evolutionary transitions of RNA-related enzymes and RNA-binding proteins, which govern the flow of genetic information. This book provides an in-depth overview on the molecular evolution of RNA-related enzymes, RNA-binding proteins, and RNA regulatory systems. The focus is not only on newly-identified RNA regulatory factors or systems that have garnered attention since the beginning of the 21st century, but it also elucidates RNA-related molecules with fundamental and significant roles in cellular genetic regulation, or the regulatory systems themselves. Specifically, the volume revisits molecules involved in transcription (RNA polymerase), pre-mRNA processing and degradation (ribonucleases such as RNase E, RNase III, and self-cleaving ribozymes), and in translation (ribosomal proteins and translation factors), regardless of their novelty. This volume thus is intended to serve as an essential resource for furthering the systematic understanding of cellular genetic regulation from a molecular evolutionary standpoint.
