Methionine vs N-formylmethionine

[w4nt2baDDS]

Is there a difference between methionine and formylmethionine (fmet)? I'm pretty sure I learned in class that fMet is what initiates translation but now I am not sure.

Appreciate any insight on this!

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[DAT Destroyer]

Is there a difference between methionine and formylmethionine (fmet)? I'm pretty sure I learned in class that fMet is what initiates translation but now I am not sure.

Appreciate any insight on this!

fMet is a starting residue in the synthesis of proteins in bacteria, and, consequently, is located at the N-terminus of the growing polypeptide. If you look at the structure of Methionine ......and compare it to f-Met,,,,you will notice the F-Met has a CHO group attached to the Nitrogen.

Hope this helps..

Dr. Romano

 

[w4nt2baDDS]

Okay, that makes sense. In Eurkaryotes a polypeptide chain is started with a regular methionine, right?

Eukaryotas = Methionine to start.
Prokaryotes = F-Met to start. Then all subsequent methionines in the polypeptide chain are just regular methionine amino acids without the additional CHO group

 

[DAT Destroyer]

Okay, that makes sense. In Eurkaryotes a polypeptide chain is started with a regular methionine, right?

Eukaryotas = Methionine to start.
Prokaryotes = F-Met to start. Then all subsequent methionines in the polypeptide chain are just regular methionine amino acids without the additional CHO group

Yes.....that is correct. Initiation of protein synthesis is done with f-met in prokaryotes only......not so in eukaryotes. The rest is similar.