Elongation factor P is dispensable in Escherichia coli and Pseudomonas aeruginosa

Curr Microbiol. 2013 Sep;67(3):293-9. doi: 10.1007/s00284-013-0363-0. Epub 2013 Apr 17.


Elongation factor P (EF-P) is a highly conserved ribosomal initiation factor responsible for stimulating formation of the first peptide bond. Its essentiality has been debated and may differ depending on the organism. Here, we demonstrate that EF-P is dispensable in Escherichia coli and Pseudomonas aeruginosa under laboratory growth conditions. Although knockouts are viable, growth rates are diminished compared with wild-type strains. Despite this cost in fitness, these mutants are not more susceptible to a wide range of antibiotics; including ribosome targeting antibiotics, such as lincomycin, chloramphenicol, and streptomycin, which have been shown previously to disrupt EF-P function in vitro. In Pseudomonas, knockout of efp leads to an upregulation of mexX, a phenotype previously observed with other genetic lesions affecting ribosome function and that can be induced by the treatment with antibiotics affecting protein synthesis.

MeSH terms

  • Escherichia coli / enzymology*
  • Escherichia coli / genetics*
  • Escherichia coli / growth & development
  • Gene Deletion*
  • Genes, Essential
  • Microbial Viability
  • Peptide Elongation Factors / genetics*
  • Peptide Elongation Factors / metabolism*
  • Pseudomonas aeruginosa / enzymology*
  • Pseudomonas aeruginosa / genetics*
  • Pseudomonas aeruginosa / growth & development


  • Peptide Elongation Factors
  • factor EF-P