GenePage for the efp gene of Escherichia coli K-12

Primary Gene Name: efp
EcoGene Accession Number: EG12099
K-12 Gene Accession Number: ECK4141
MG1655 Gene Identifier: b4147
Gene Name Mnemonic: Elongation Factor-Peptidyltransferase
Alternate Gene Symbols: None
Description: Polyproline-specific translation elongation factor EF-P
  # bp Upstream # bp Downstream
Verified Start MW: 20591.31 ---------188 aa Pre-Run BlastP UniProt
Pre-Run BlastP NR+Env
Left End: 4375699
Left Intergenic Region

Name: epmB_efp

Length: 41 bp gap

Orientation: Divergent

Left_end: 4375658

Right_end: 4375698

Centisome: 94.27

Genomic Address
Minute or Centisome (%) = 94.27
Right End: 4376265
Right Intergenic Region

Name: efp_ecnA

Length: 51 bp gap

Orientation: Codirectional+

Left_end: 4376266

Right_end: 4376316

Centisome: 94.28

Lysine34-lysylated EF-P functions to unblock translation stalled at polyproline; the maximal stalling effect of polyproline is seen with three consecutive prolines, although Pro-Pro-Gly also blocked translation in the absence of EF-P (Doerfel, 2012; Ude, 2012). epmC(yfcM) mutants do not display the pleiotropic and slow-growth phenotypes observed for epmAB or efp mutants in either E. coli or Salmonella, suggesting that the EpmC-mediated modification of EF-P is is not required for the translation of polyproline-containing proteins, the function of EF-P requiring the EpmAB-mediated lysine34 lysylation (Bullwinkle, 2012). EF-P is present at one copy per ten ribosomes (An, 1980). efp has been reported to be an essential gene (Aoki, 1997) and to be a non-essential gene (Baba, 2006). The S. typhi efp gene is non-essential (Langridge, 2009). EF-P is homologous to eukaryotic initiation factor eIF-5A (Kyrpides, 1998). The previously reported function of EF-P to stimulate initial peptide bond formation has been recently challenged and appears not to be a critical function of EF-P (Ganoza, 2000; Blaha, 2009; Bullwinkle, 2012). The crystal structure of EF-P from T. thermophilus (PDB:1UEB) shows that, like other translation factors, EF-P is a tRNA mimic (Hanawa-Suetsugu, 2004). The T. thermophilus crystal structure of EF-P bound to ribosomes (PDB:3HUW) shows that the tRNA-like EF-P does not bind to tRNA binding sites in the ribosome, but rather binds between the P-site and the E-site, although footprinting experiments had previously shown binding to the A-site (Aoki, 2008; Blaha, 2009). EF-P appears to assist in the proper positioning of the fMet-tRNA for the formation of the first peptide bond (Aoki, 2008; Blaha, 2009). An earlier report that EF-P Lys34 is modified with spermidine has been refuted; the Lys34 is modified with lysine (Aoki, 2008 ; Yanagisawa, 2010). A Lys reside in eucaryotic eIF5A homologous to EF-P Lys34 is modified with hypusine (Chen, 1997). EpmA(YjeA) and EpmB(YjeK) are required to modify EF-P Lys34 by lysylation of the epsilon amino group; failure to modify EF-P with lysine results in a slow growth defect; EpmB(YjeK) may convert alpha-lysyl-EF-P to beta-lysyl-EF-P (Yanagisawa, 2010). EpmA(YjeA) and EpmB(YjeK) were predicted to be responsible for the modification of EF-P-Lys34 with spermidine, but Lys34 is actually modified with another lysine, not spermidine; epmB(yjeK) is in the efp genetic neighborhood in many strains and all genomes that have the conserved Lys34 in EF-P have epmB(yjeK) orthologs; EpmB(YjeK) is a lysine 2,3-aminomutase homolog (but in a different clade) (Bailly, 2010; Yanagisawa, 2010). Binds TrxA (Kumar, 2004). A third and final EF-P post-translation modification enzyme EpmC(YfcM) is identified as EF-P-Lys34 hydroxylase; EpmC(YfcM) acts after beta-lysinylation of Lys34 by EpmA(YjeA) and EpmB(YjeK); EpmC(YfcM) adds an oxygen atom to the C5 position of Lys34 and does not modify the added beta-lysine; YjeA and YjeK were renamed as EpmA and EpmB, respectively (Peil, 2012).

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