The Catalyst: RNA and the Quest to Unlock Life's Deepest Secrets

part of their immune surveillance, cells have a natural mechanism for chopping proteins into little pieces and presenting them on their outer surface, where they can be surveyed by T cells.

Alternative mRNA splicing is often regulated by tissue-specific proteins called splicing factors, which bind to certain sequences on the precursor mRNA and either enhance or discourage the use of certain splice sites.

abbreviated RNAase or RNase,

In prebiotic times—that is, before the emergence of the first life-form—the bricks would have to form spontaneously from chemicals present in the environment.

The U2 snRNA base-paired with a complementary sequence near the end of the intron, but it was a protein associated with the U2 snRNA that recognized the AG splice site.

true mRNA would need to be unstable to allow rapid changes in what proteins were being made.

With a sequence complementary to that of the codon, this triplet is called the anticodon.

proteins that allow double-stranded RNA to silence gene expression.

unusual set of Tetrahymena genes that existed as minichromosomes, each less than a thousandth the size of the smallest human chromosome. These individual DNA molecules harbored Tetrahymena’s ribosomal RNA genes.