Enzymology of RNA cap synthesis

Wiley Interdiscip Rev RNA. 2010 Jul-Aug;1(1):152-72. doi: 10.1002/wrna.19. Epub 2010 May 25.

Abstract

The 5' guanine-N7 methyl cap is unique to cellular and viral messenger RNA (mRNA) and is the first co-transcriptional modification of mRNA. The mRNA cap plays a pivotal role in mRNA biogenesis and stability, and is essential for efficient splicing, mRNA export, and translation. Capping occurs by a series of three enzymatic reactions that results in formation of N7-methyl guanosine linked through a 5'-5' inverted triphosphate bridge to the first nucleotide of a nascent transcript. Capping of cellular mRNA occurs co-transcriptionally and in vivo requires that the capping apparatus be physically associated with the RNA polymerase II elongation complex. Certain capped mRNAs undergo further methylation to generate distinct cap structures. Although mRNA capping is conserved among viruses and eukaryotes, some viruses have adopted strategies for capping mRNA that are distinct from the cellular mRNA capping pathway.

Publication types

  • Review

MeSH terms

  • Acid Anhydride Hydrolases / genetics
  • Acid Anhydride Hydrolases / metabolism
  • Acid Anhydride Hydrolases / physiology
  • Animals
  • Enzymes / metabolism
  • Enzymes / physiology*
  • Humans
  • Models, Biological
  • Models, Molecular
  • Nucleic Acid Conformation
  • Nucleotidyltransferases / genetics
  • Nucleotidyltransferases / metabolism
  • Nucleotidyltransferases / physiology
  • RNA Caps / biosynthesis*
  • RNA Caps / chemistry
  • RNA Caps / genetics
  • RNA Processing, Post-Transcriptional
  • RNA, Messenger / chemistry
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • RNA, Viral / chemistry
  • RNA, Viral / genetics
  • RNA, Viral / metabolism

Substances

  • Enzymes
  • RNA Caps
  • RNA, Messenger
  • RNA, Viral
  • Nucleotidyltransferases
  • mRNA guanylyltransferase
  • Acid Anhydride Hydrolases
  • RNA triphosphatase