Evolutionary aspects of plastid proteins involved in transcription: the transcription of a tiny genome is mediated by a complicated machinery

Transcription. Nov-Dec 2012;3(6):290-4. doi: 10.4161/trns.21810. Epub 2012 Aug 14.


Chloroplasts in land plants have a small genome consisting of only 100 genes encoding partial sets of proteins for photosynthesis, transcription and translation. Although it has been thought that chloroplast transcription is mediated by a basically cyanobacterium-derived system, due to the endosymbiotic origin of plastids, recent studies suggest the existence of a hybrid transcription machinery containing non-bacterial proteins that have been newly acquired during plant evolution. Here, we highlight chloroplast-specific non-bacterial transcription mechanisms by which land plant chloroplasts have gained novel functions.

Keywords: NEP; PEP; chloroplast; nucleoid; pTAC.

MeSH terms

  • Chloroplast Proteins / genetics*
  • Chloroplasts / genetics*
  • Evolution, Molecular
  • Genome, Plant*
  • Plants / genetics
  • Transcription, Genetic


  • Chloroplast Proteins