RNA Transcription, Processing, Modification and Translation

RNA is the most versatile macromolecule in nature. The linear sequence of an RNA can encode large amounts of complex information that is subsequently transformed into functional proteins. However, many RNA sequences also contain sufficient information to fold themselves into specific shapes with distinct chemical properties. Thus, RNA is unique amongst biopolymers in that it encodes genetic information, provides structural scaffolding, recognizes and transports other molecules and carries out many forms of chemical catalysis in the cell. For example, messenger RNA (mRNA) encodes protein sequences, transfer RNA (tRNA) acts at the ribosome to decode mRNA information to specify particular amino acids, ribosomal RNAs (rRNA) assemble into the ribosome where protein is manufactured, small nuclear RNAs (snRNAs) tailor other RNAs to the proper size and microRNAs (miRNAs) are tiny sequences that bind and regulate the function of other RNAs. In this chapter, we focus on the lives of the many cellular RNA species – how they are generated, modified and regulated and play central roles in the flow of genetic information.