mRNA structure
Messenger RNA, which is usually abbreviated as mRNA, plays a central role in expressing genetic information. Messenger RNA is a form of RNA which connects two processes as a messenger (messenger): the transcription, which transfers a piece of DNA (a gene) into mRNA, and the translation, translating the mRNA into a chain of amino acids (a protein). In organisms, RNA is usually single-stranded and can take very complex three-dimensional structures while DNA is double-stranded. Double-stranded RNA occurs in the genetic material of some RNA viruses, and plays a role in cellular immunity in plants.
schematically
Over the years, it has been discovered that after the transcription, many other processes are taking place. Hereby the mRNA is processed before being translated. The most important of these processes are: RNA processing, splicing and RNA editing. The raw RNA, as formed immediately after transcription, is then called pre-mRNA. The processed RNA, as translated, is simply called mRNA. The scheme now looks like this: Also see
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