Cotranslational processing mechanisms: towards a dynamic 3D model

Trends Biochem Sci. 2009 Aug;34(8):417-26. doi: 10.1016/j.tibs.2009.04.003. Epub 2009 Jul 31.


Recent major advances have been made in understanding how cotranslational events are achieved in the course of protein biosynthesis. Specifically, several studies have shed light into the dynamic process of how nascent chains emerging from the ribosome are supported by protein biogenesis factors to ensure both processing and folding mechanisms. To take into account the awareness that coordination is needed, a new 'concerted model' recently proposed simultaneous action of both processes on the ribosome. In the model, any emerging nascent chain is first encountered by the chaperone trigger factor (TF), which forms an open cradle underneath the ribosomal exit tunnel. This cradle serves as a passive router that channels the nascent chains to the first cotranslational event, the proteolysis event performed by the N-terminal methionine excision machinery. Although fascinating, this model clearly raises more questions than it answers. Does the data used to develop this model stand up to scrutiny and, if not, what are the alternative mechanisms that the data suggest?

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Amidohydrolases / chemistry
  • Amidohydrolases / genetics
  • Amidohydrolases / metabolism
  • Amino Acid Sequence
  • Bacterial Proteins / chemistry
  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism*
  • Models, Biological
  • Models, Molecular*
  • Molecular Sequence Data
  • Peptidylprolyl Isomerase / chemistry
  • Peptidylprolyl Isomerase / genetics
  • Peptidylprolyl Isomerase / metabolism
  • Protein Biosynthesis*
  • Protein Conformation
  • Ribosomes / chemistry
  • Ribosomes / genetics
  • Ribosomes / metabolism*


  • Bacterial Proteins
  • Amidohydrolases
  • peptide deformylase
  • Peptidylprolyl Isomerase