N-formyl-methionine

Definition

N-formyl-methionine (fMet) is a derivative of the amino acid methionine, with a formyl group added to its amino group. It serves as the initial amino acid incorporated during the synthesis of proteins in prokaryotes and in the mitochondria and chloroplasts of eukaryotes.

5 Must Know Facts For Your Next Test

1. fMet is used specifically in the initiation of protein synthesis in prokaryotic organisms.
2. The formyl group on fMet allows it to be recognized by the ribosome's P-site during translation initiation.
3. In eukaryotic cells, methionine (not N-formyl-methionine) is used for initiating protein synthesis.
4. After initiation, the formyl group can be removed from fMet by peptide deformylase, allowing normal methionine function.
5. The presence of fMet can trigger an immune response in mammals, as it is often associated with bacterial infections.

Review Questions

Related terms

Translation Initiation: The process where ribosomes assemble on mRNA to begin protein synthesis.

Peptide Deformylase: An enzyme that removes the formyl group from fMet after initiation.

Ribosome P-site: The site on the ribosome where the first aminoacyl-tRNA binds during translation initiation.