N-Formylmethionine (fMet, [2] HCO-Met, [3] For-Met [3]) is a derivative of the amino acid methionine in which a formyl group has been added to the amino group. It is specifically used for initiation of protein synthesis from bacterial and organellar …

Different roles of N-formylmethionine (fMet) in different species and organelles. fMet was initially found in the translation process of bacteria, chloroplast, and mitochondria. Moreover, fMet promotes protein complex formation in mitochondria and works as …

N-formyl-L-methionine is a L-methionine derivative in which one of the hydrogens attached to the nitrogen is replaced by a formyl group. It has a role as a metabolite. It is a proteinogenic amino acid, a N-formyl amino acid and a L-methionine derivative. …

N -Formylmethionine (fMet) is the amino acid coded by the AUG codon, which is the start codon for protein synthesis. Therefore, fMet is the N-terminal amino acid of nearly all proteins in prokaryotic systems; however it is commonly removed posttranslationally.

The question is posed in terms which imply that the formylation of the initiating methionine (Met) of protein synthesis was a relatively late evolutionary development for some purpose not concerned with translation, such as allowing regulation of protein degradation.

The first amino acid in the synthesis of all bacterial polypeptides is N-formylmethionine (fMet), i.e. a modified methionine residue with a formyl group attached to its amino group. Two types of methionyl-tRNA exist; one binds formylmethionine and the other, normal methionine.

However, the methionine of charged tRNA fMet is immediately recognized by another enzyme, tRNA methionyl transformylase, which transfers a formyl group from N 10-formyltetrahydrofolate (fTHF) to the amino group of the methionine to form N-formylmethionine (fMet) (as follows).