Virtuelle (Nano) Welten PDB Molecule of the Month 82: Elongation Factors

Moving On

After the ribosome has attached the amino acid to the growing chain, it needs to shift the tRNA molecules, ejecting the spent one and creating room for the next one to bind. EF-G performs this task. As you can see from this structure of a bacterial EF-G (PDB entry 1dar, on the left), it is very similar in shape to the complex of EF-Tu and tRNA. Powered by GTP, EF-G binds to the ribosome, ejects the tRNA, and shifts the mRNA by one codon. As shown in the next page, this may involve a large change in shape.