GTPase Linked Elongation Factors, commonly known as GTPase EFs, are a group of proteins that play a crucial role in protein synthesis. They are responsible for the elongation phase of translation, which is the process of assembling amino acids into a polypeptide chain according to the mRNA sequence.
GTPase EFs are named after their ability to bind and hydrolyze guanosine triphosphate (GTP), a nucleotide molecule. The hydrolysis of GTP is an important step in the energy-dependent process of ribosome translocation, where the ribosome moves along the mRNA molecule to incorporate the next amino acid into the growing polypeptide chain.
There are three main types of GTPase EFs: EF-Tu, EF-G, and EF-4. EF-Tu, also known as elongation factor thermo unstable, is responsible for delivering the aminoacyl-tRNA to the ribosome during the elongation phase. It forms a complex with GTP and binds to the aminoacyl-tRNA, ensuring accurate positioning of the incoming amino acid.
Once the aminoacyl-tRNA is bound to the ribosome, GTP is hydrolyzed to GDP, and EF-Tu-GDP is released. EF-G then binds to the ribosome and promotes the translocation of the ribosome along the mRNA, allowing the next codon to be exposed for amino acid incorporation. Lastly, EF-4 stimulates the reversal of potential backward steps during translation, enhancing the fidelity of protein synthesis.
In summary, GTPase Linked Elongation Factors are essential proteins that regulate the elongation phase of translation by binding to GTP and promoting ribosome movement along the mRNA molecule. Their role ensures accurate and efficient protein synthesis in cells.
