The aminoacyl-tRNA synthetases are an essential and universally distributed family of
enzymes that plays a critical role in protein synthesis, pairing tRNAs with their cognate …

▪ Abstract In vitro selection allows rare functional RNA or DNA molecules to be isolated from
pools of over 1015 different sequences. This approach has been used to identify RNA and …

During evolution, there have been several major changes in the way that genetic information
is organized and transmitted from one generation to the next. These transitions include the …

It is becoming increasingly clear that RNA is more than a passive carrier of genetic
information. Folded RNA molecules play key roles in almost every aspect of cellular …

It is generally accepted that DNA appeared after RNA during the chemical evolution of life.
To synthesize DNA, deoxyribonucleotides are required as building blocks. At present, these …

Ribozymes are an important new class of metalloenzymes that have an unlikely feature: they
are made entirely of ribonucleic acid (RNA). Metal ions are essential for efficient chemical …

An attractive solution to the problem of the origin of protein synthesis in an evolving 'RNA
world'involves catalysis by nucleic acid without assistance from proteins,. Indeed, even the …

An RNA has been selected that rapidly aminoacylates its 2′(3′) terminus when provided
with phenylalanyl-adenosine monophosphate. That is, the RNA accelerates the same …

1Current usage provides at least two alternative nomenclatures for these enzymes. The
more widely used convention combines the three-letter amino acid abbreviation with the …

Group I and group II introns are two types of RNA enzymes, ribozymes, that catalyze their
own splicing by different mechanisms. In this review, we summarize current information …