Biology:Elongation factor P

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Elongation factor P (EF-P) KOW-like domain
PDB 1iz6 EBI.jpg
crystal structure of translation initiation factor 5a from pyrococcus horikoshii
Identifiers
SymbolEFP_N
PfamPF08207
Pfam clanCL0107
InterProIPR013185
PROSITEPDOC00981
Elongation factor P (EF-P) OB domain
PDB 1ueb EBI.jpg
crystal structure of translation elongation factor p from thermus thermophilus hb8
Identifiers
SymbolEFP
PfamPF01132
Pfam clanCL0021
InterProIPR001059
PROSITEPDOC00981
CDDcd04470
Elongation factor P, C-terminal
PDB 1ueb EBI.jpg
crystal structure of translation elongation factor p from thermus thermophilus hb8
Identifiers
SymbolElong-fact-P_C
PfamPF09285
InterProIPR015365
SCOP21ueb / SCOPe / SUPFAM
CDDcd05794

EF-P (elongation factor P) is an essential protein that in bacteria stimulates the formation of the first peptide bonds in protein synthesis.[1][2] Studies show that EF-P prevents ribosomes from stalling during the synthesis of proteins containing consecutive prolines.[1] EF-P binds to a site located between the binding site for the peptidyl tRNA (P site) and the exiting tRNA (E site). It spans both ribosomal subunits with its amino-terminal domain positioned adjacent to the aminoacyl acceptor stem and its carboxyl-terminal domain positioned next to the anticodon stem-loop of the P site-bound initiator tRNA.[3] The EF-P protein shape and size is very similar to a tRNA and interacts with the ribosome via the exit “E” site on the 30S subunit and the peptidyl-transferase center (PTC) of the 50S subunit.[4] EF-P is a translation aspect of an unknown function,[1] therefore It probably functions indirectly by altering the affinity of the ribosome for aminoacyl-tRNA, thus increasing their reactivity as acceptors for peptidyl transferase.

EF-P consists of three domains:

  • An N-terminal KOW-like domain
  • A central OB domain, which forms an oligonucleotide-binding fold. It is not clear if this region is involved in binding nucleic acids[5]
  • A C-terminal domain which adopts an OB-fold, with five beta-strands forming a beta-barrel in a Greek-key topology[5]

Eukaryotes and archaea lack EF-P. In these domains, a similar function is performed by the archaeo-eukaryotic initiation factor, a/eIF-5A, which exhibits some modest sequence and structural similarity with EF-P.[2][6] There are, however, important differences between EF-p and eIF-5A. (a) EF-P has a structure similar to that of L-shaped tRNA and it contains three (I,II and III) β-barrel domains. In contrast, eIF-5A contains only two domains (C and N) with a corresponding size difference.[2] (b) Moreover, as opposed to eIF-5A, which contains the non-proteinogenic amino acid hypusine that is essential for its activity, EF-P displays a diversity of post-transcriptional modifications at the analogous position (β-lysylation of lysine residue, rhamnosylation of arginine residue, or none at all).[7][8]

Function

In eubacteria, there are three groups of factors that promote protein synthesis: initiation factors, elongation factors and termination factors.[7] The elongation phase of translation is promoted by three universal elongation factors, EF-Tu, EF-Ts, and EF-G.[9] EF-P was discovered in 1975 by Glick and Ganoza,[10] as a factor that increased the yield of peptide bond formation between initiator fMet-tRNA(fMet) and a mimic of aa-tRNA, puromycin (Pmn). The low yield of product formation in absence of EF-P can be described by the loss of peptidyl-tRNA from the stalled ribosome. Thus, EF-P is not a necessary component of minimal in vitro of translation system, however, the absence of EF-P can limit translation rate, increase antibiotic sensitivity, and slow growth.

To complete its function, EF-P enters paused ribosomes through the E-site and facilitates peptide bond formation through interactions with the P-site tRNA.[11] EF-P and eIF-5A both are essential for the synthesis of a subset of proteins containing proline stretches in all cells.[1]

It has been suggested that after binding of the initiator tRNA to the P/I site, it is correctly positioned to the P site by binding of EF-P to the E site.[12] Additionally, EF-P has been shown to assist in efficient translation of three or more consecutive proline residues.[13]

Structure

EF-P is a 21 kDa protein encoded by the efp gene.[9] EF-P consists of three β-barrel domains (I,II and III) and has a L shape tRNA structure. Domain II and III of EF-P are similar to each other. Despite the structural similarity of EF-P with tRNA, studies showed that EF-P does not bind to the ribosome at the classical tRNA binding site, but at the distinct position that is located between the P and E sites.[3]

See also

References

  1. 1.0 1.1 1.2 1.3 "EF-P is essential for rapid synthesis of proteins containing consecutive proline residues". Science 339 (6115): 85–8. January 2013. doi:10.1126/science.1229017. PMID 23239624. Bibcode2013Sci...339...85D. 
  2. 2.0 2.1 2.2 "Crystal structure of elongation factor P from Thermus thermophilus HB8". Proceedings of the National Academy of Sciences of the United States of America 101 (26): 9595–600. June 2004. doi:10.1073/pnas.0308667101. PMID 15210970. Bibcode2004PNAS..101.9595H. 
  3. 3.0 3.1 "Formation of the first peptide bond: the structure of EF-P bound to the 70S ribosome". Science 325 (5943): 966–70. August 2009. doi:10.1126/science.1175800. PMID 19696344. Bibcode2009Sci...325..966B. 
  4. "EF-P dependent pauses integrate proximal and distal signals during translation". PLOS Genetics 10 (8): e1004553. August 2014. doi:10.1371/journal.pgen.1004553. PMID 25144653. 
  5. 5.0 5.1 "Crystal structure of elongation factor P from Thermus thermophilus HB8". Proceedings of the National Academy of Sciences of the United States of America 101 (26): 9595–600. June 2004. doi:10.1073/pnas.0308667101. PMID 15210970. Bibcode2004PNAS..101.9595H. 
  6. "eIF5A and EF-P: two unique translation factors are now traveling the same road". Wiley Interdisciplinary Reviews. RNA 5 (2): 209–22. 2013. doi:10.1002/wrna.1211. PMID 24402910. 
  7. 7.0 7.1 "Post-translational modification by β-lysylation is required for activity of Escherichia coli elongation factor P (EF-P)". The Journal of Biological Chemistry 287 (4): 2579–90. January 2012. doi:10.1074/jbc.M111.309633. PMID 22128152. 
  8. Volkwein, Wolfram; Krafczyk, Ralph; Jagtap, Pravin Kumar Ankush; Parr, Marina; Mankina, Elena; Macošek, Jakub; Guo, Zhenghuan; Fürst, Maximilian Josef Ludwig Johannes et al. (24 May 2019). "Switching the Post-translational Modification of Translation Elongation Factor EF-P". Frontiers in Microbiology 10: 1148. doi:10.3389/fmicb.2019.01148. PMID 31178848. 
  9. 9.0 9.1 "Elongation factor P: Function and effects on bacterial fitness". Biopolymers 99 (11): 837–45. November 2013. doi:10.1002/bip.22341. PMID 23828669. 
  10. "Identification of a soluble protein that stimulates peptide bond synthesis". Proceedings of the National Academy of Sciences of the United States of America 72 (11): 4257–60. November 1975. doi:10.1073/pnas.72.11.4257. PMID 1105576. Bibcode1975PNAS...72.4257G. 
  11. "Elongation factor P is required to maintain proteome homeostasis at high growth rate". Proceedings of the National Academy of Sciences of the United States of America 115 (43): 11072–11077. October 2018. doi:10.1073/pnas.1812025115. PMID 30297417. Bibcode2018PNAS..11511072T. 
  12. "Leaps in translational elongation.". Science 326 (5953): 677–8. October 2009. doi:10.1126/science.1181511. PMID 19833922. 
  13. "Translation elongation factor EF-P alleviates ribosome stalling at polyproline stretches". Science 339 (6115): 82–5. January 2013. doi:10.1126/science.1228985. PMID 23239623. Bibcode2013Sci...339...82U. 
This article incorporates text from the public domain Pfam and InterPro: IPR001059
This article incorporates text from the public domain Pfam and InterPro: IPR015365