Elongation factor: Difference between revisions

Latest revision as of 11:06, 15 February 2025

Elongation Factor[edit]

Elongation Factor Tu bound to GDP

Elongation factors are a set of proteins that play a crucial role in the process of protein synthesis by facilitating the elongation phase of translation. These factors are essential for the accurate and efficient addition of amino acids to the growing polypeptide chain during ribosomal translation of mRNA.

Types of Elongation Factors[edit]

There are several types of elongation factors, each with specific functions in the translation process. The most well-known elongation factors include:

Elongation Factor Tu (EF-Tu)[edit]

Elongation Factor Tu (EF-Tu) is a GTP-binding protein that plays a key role in the delivery of aminoacyl-tRNA to the A site of the ribosome. EF-Tu binds to aminoacyl-tRNA in a GTP-dependent manner and escorts it to the ribosome. Upon correct codon-anticodon pairing, GTP is hydrolyzed, and EF-Tu is released, allowing the aminoacyl-tRNA to participate in peptide bond formation.

Elongation Factor G (EF-G)[edit]

Elongation Factor G (EF-G) is involved in the translocation step of translation. After peptide bond formation, EF-G binds to the ribosome and facilitates the movement of tRNA and mRNA through the ribosome, allowing the next codon to be positioned in the A site. This process is also GTP-dependent.

Elongation Factor Ts (EF-Ts)[edit]

Elongation Factor Ts (EF-Ts) acts as a guanine nucleotide exchange factor for EF-Tu. It catalyzes the release of GDP from EF-Tu, allowing GTP to bind and reactivate EF-Tu for another round of aminoacyl-tRNA delivery.

Function in Translation[edit]

During the elongation phase of translation, elongation factors ensure the correct and efficient addition of amino acids to the growing polypeptide chain. The process involves several steps:

Aminoacyl-tRNA Binding: EF-Tu delivers the correct aminoacyl-tRNA to the A site of the ribosome.
Peptide Bond Formation: The ribosome catalyzes the formation of a peptide bond between the amino acid in the A site and the growing polypeptide chain in the P site.
Translocation: EF-G facilitates the movement of tRNA and mRNA, shifting the ribosome along the mRNA to position the next codon in the A site.

Importance in Cellular Function[edit]

Elongation factors are vital for cellular function as they ensure the fidelity and efficiency of protein synthesis. Errors in translation can lead to the production of malfunctioning proteins, which can have deleterious effects on cell function and viability.

Related Pages[edit]

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-'''Elongation Factor''' (EF) refers to a set of proteins that play a crucial role in the [[protein synthesis]] process within the [[cell (biology)|cell]]. These factors are essential for the [[translation (biology)|translation]] phase of protein synthesis, where they facilitate the elongation of the nascent [[polypeptide]] chain by adding [[amino acids]] to the chain. Elongation factors are found in both [[prokaryotes]] and [[eukaryotes]], although their specific functions and mechanisms can vary between these two types of organisms.
+== Elongation Factor ==
-==Function==
+[[File:081-EF-Tu-1ttt.jpg|thumb|right|Elongation Factor Tu bound to GDP]]
-The primary function of elongation factors is to ensure the efficient and accurate elongation of the polypeptide chain during translation. This involves several key steps:
-* '''Delivery of Aminoacyl-tRNAs''': Elongation factors like EF-Tu in prokaryotes and eEF1A in eukaryotes bind to [[aminoacyl-tRNA]] and deliver it to the A site of the [[ribosome]].
-* '''Translocation''': After the formation of a new peptide bond, the ribosome must move, or translocate, along the mRNA to allow the next aminoacyl-tRNA to enter the A site. EF-G in prokaryotes and eEF2 in eukaryotes are responsible for this process.
-* '''Accuracy and Fidelity''': Elongation factors also play a role in ensuring the accuracy of codon-anticodon pairing, thereby reducing the likelihood of [[mutation]]s.
-==Types==
+Elongation factors are a set of proteins that play a crucial role in the process of [[protein synthesis]] by facilitating the elongation phase of [[translation (biology)|translation]]. These factors are essential for the accurate and efficient addition of [[amino acids]] to the growing [[polypeptide chain]] during [[ribosome|ribosomal]] translation of [[mRNA]].
-There are several types of elongation factors, each with a specific role in the process of translation elongation:
-* '''EF-Tu''' (prokaryotes) / '''eEF1A''' (eukaryotes): Responsible for the delivery of aminoacyl-tRNA to the ribosome.
-* '''EF-Ts''': Acts as a guanine nucleotide exchange factor for EF-Tu, regenerating EF-Tu in its GTP-bound state.
-* '''EF-G''' (prokaryotes) / '''eEF2''' (eukaryotes): Catalyzes the translocation of the ribosome along the mRNA.
-* '''EF-P''' (prokaryotes) / '''eIF5A''' (eukaryotes): Enhances the translation of proline-rich sequences by facilitating the entry of peptidyl-tRNA to the P site of the ribosome.
-==Clinical Significance==
+== Types of Elongation Factors ==
-Elongation factors are not only fundamental to the biology of the cell but also have implications in medicine and pharmacology. For example, certain antibiotics, such as [[diphtheria toxin]], target elongation factors like eEF2, inhibiting protein synthesis and thereby killing bacterial cells. Additionally, mutations or dysregulation in the genes encoding elongation factors can lead to diseases, including cancer, due to the critical role these proteins play in cell growth and proliferation.
-==Research and Applications==
+There are several types of elongation factors, each with specific functions in the translation process. The most well-known elongation factors include:
-Research into elongation factors continues to uncover their complex roles in cellular processes beyond translation, including their involvement in the regulation of gene expression and their potential as targets for therapeutic intervention. The study of elongation factors is also contributing to the development of novel antibiotics and treatments for diseases caused by protein synthesis dysregulation.
+=== Elongation Factor Tu (EF-Tu) ===
+[[Elongation Factor Tu]] (EF-Tu) is a GTP-binding protein that plays a key role in the delivery of aminoacyl-tRNA to the A site of the ribosome. EF-Tu binds to aminoacyl-tRNA in a GTP-dependent manner and escorts it to the ribosome. Upon correct codon-anticodon pairing, GTP is hydrolyzed, and EF-Tu is released, allowing the aminoacyl-tRNA to participate in peptide bond formation.
+=== Elongation Factor G (EF-G) ===
+[[Elongation Factor G]] (EF-G) is involved in the translocation step of translation. After peptide bond formation, EF-G binds to the ribosome and facilitates the movement of tRNA and mRNA through the ribosome, allowing the next codon to be positioned in the A site. This process is also GTP-dependent.
+=== Elongation Factor Ts (EF-Ts) ===
+[[Elongation Factor Ts]] (EF-Ts) acts as a guanine nucleotide exchange factor for EF-Tu. It catalyzes the release of GDP from EF-Tu, allowing GTP to bind and reactivate EF-Tu for another round of aminoacyl-tRNA delivery.
+== Function in Translation ==
+During the elongation phase of translation, elongation factors ensure the correct and efficient addition of amino acids to the growing polypeptide chain. The process involves several steps:
+# '''Aminoacyl-tRNA Binding:''' EF-Tu delivers the correct aminoacyl-tRNA to the A site of the ribosome.
+# '''Peptide Bond Formation:''' The ribosome catalyzes the formation of a peptide bond between the amino acid in the A site and the growing polypeptide chain in the P site.
+# '''Translocation:''' EF-G facilitates the movement of tRNA and mRNA, shifting the ribosome along the mRNA to position the next codon in the A site.
+== Importance in Cellular Function ==
+Elongation factors are vital for cellular function as they ensure the fidelity and efficiency of protein synthesis. Errors in translation can lead to the production of malfunctioning proteins, which can have deleterious effects on cell function and viability.
+== Related Pages ==
+* [[Translation (biology)]]
+* [[Ribosome]]
+* [[Protein synthesis]]
+* [[Aminoacyl-tRNA]]
-[[Category:Cell biology]]
-[[Category:Molecular biology]]
 [[Category:Protein biosynthesis]]
-{{Molecular-biology-stub}}
-{{medicine-stub}}