Related words. 1  post verb. 2  post up phrasal verb. 3  post off phrasal verb.  cross-post 1  verb. 1. a public notice, especially one advertising a job Synonyms and related words. Types of advertisement:ad, advert, advertisement...  2. a job that someone is sent somewhere to do, usually in another country Synonyms and related words.
Catalytic RNAs, or ribozymes, are a fossil record of the ancient molecular evolution of life on Earth and still provide the essential core of macromolecule synthesis in all life forms today.
For many years, it was believed that the only enzymes were proteins and their cofactors. Recently, however, several RNA enzymes have been discovered. These enzymes are called ribozymes and exhibit all the same features (specificity, transition state stabilization, Michaelis Menten kinetics) as protein enzymes. One group of ribozymes is known as hammerhead ribozymes.