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Messenger RNA in Prokaryotes

  1. Sidney R Kushner

Published Online: 15 MAY 2014

DOI: 10.1002/9780470015902.a0000874.pub3

eLS

eLS

How to Cite

Kushner, S. R. 2014. Messenger RNA in Prokaryotes. eLS. .

Author Information

  1. University of Georgia, Athens, Georgia, USA

Publication History

  1. Published Online: 15 MAY 2014

Abstract

Messenger ribonucleic acids (mRNAs) are molecules that represent the intermediate step in the conversion of genetic information carried in a cell's deoxyribonucleic acid (DNA) into functional proteins. They are synthesised by the enzyme RNA polymerase, which recognises specific sequences in the DNA (promoters) to initiate the process called transcription. Downstream sequences, called terminators, provide the signals for transcription to stop. Structural features of mRNAs, such as the presence of a strong ribosome-binding site (RBS) and appropriate spacing between the RBS and the translation start codon, control both how effectively the information they contain is translated into functional proteins and how rapidly they are decayed. The steady-state level of each mRNA, which is determined by the rate of its synthesis versus the rate of its decay, helps regulate how much protein is synthesised from each mRNA. mRNA decay in prokaryotes is carried out by a series of nucleases that can either degrade the RNA molecule by cleaving at internal sites or removing one nucleotide at a time from either the 5′ or 3′ terminus.

Key Concepts:

  • RNA is distinguished from DNA by the presence of ribose instead of deoxyribose and uracil instead of thymine.

  • Messenger RNAs are required for converting the genetic information in the DNA into functional proteins.

  • More than one protein can be encoded in a single mRNA.

  • In prokaryotes mRNAs must have a ribosome binding site in order to be translated.

  • Secondary and tertiary structures within an mRNA affect its stability and functionality.

  • Riboswitches help regulate the expression of a large number of genes.

  • mRNAs are degraded by a variety of ribonucleases.

  • mRNA decay is carried out by multiprotein complexes in bacteria.

  • Polyadenylation of mRNAs in bacteria stimulate their degradation.

  • The translation and stability of many mRNAs are regulated by sRNAs.

Keywords:

  • transcription;
  • translation;
  • ribonucleases;
  • polyadenylation;
  • decay;
  • riboswitch;
  • small regulatory RNA