Sandbox Reserved 307: Difference between revisions

<scene name='Sandbox_Reserved_307/Removal/1'>Residues 40-44 and 260-263</scene> are disordered when EF-Tu-MgGDP undergoes trypsin modification <ref name="gp"/>. In addition, residues 1-7 and 45-58 are removed, the latter of which makes up the Switch I loop <ref name="gp"/>. The Switch I loop conformation that is regulated by the binding of MgGDP and MgGTP. The presence of tetracycline may affect the conversion rate between the EF-Tu-MgGTP and EF-Tu-MgGDP conformations, affecting the interaction with the ribosome <ref name="gp"/>. In this way, tetracycline may act to inhibit protein synthesis by preventing the binding of aminoacyl-tRNA to the A site of the ribosome.  

EF-Tu binds an aminoacylated tRNA molecule in the cytoplasm and allows entry into the ribosome <ref name="gp"/>. EF-Tu binds a cavity between the 30S and 50S ribosomal subunits, while the tRNA anticodon associates with the mRNA codon in the A site of the ribosome <ref name="gp3">PMID: 19536129 </ref>.. If the pairing is incorrect, the tRNA will likely leave the ribosome. However, if a correct pairing has occurred, EF-Tu hydrolyzes guanosine triphosphate (GTP) to the diphosphate form (GDP)<ref name="gp"/>. This hydrolysis results in a change in conformation, releasing the tRNA into the ribosome. The dissociation allows the tRNA molecule to then completely interact with the A site of the ribosome the amino acid on the tRNA can be transferred to the growing peptide chain via covalent bond formation <ref name="gp"/>. The GDP-bound EF-Tu molecule can then interact with EF-Ts, which exchanges the GDP for a new GTP and prepares EF-Tu to interact with another charged amino acid, once EF-G has acted for translocation along the mRNA sequecne. In this way, EF-Tu is a vital component in the propcess of lengthening a peptide during protein synthesis.[[Image:EF-TUFigure.jpg | frame="true" | caption='EF-Tu and EF-G cycle during protein synthesis at the ribosome']]