Peptidyl transferase
Encyclopedia
The Peptidyl transferase is an aminoacyltransferase
Aminoacyltransferases
Aminoacyltransferases are acyltransferase enzymes which act upon an amino group.They are classified under "2.3.2" in the EC number system....

  as well as the primary enzymatic function of the ribosome
Ribosome
A ribosome is a component of cells that assembles the twenty specific amino acid molecules to form the particular protein molecule determined by the nucleotide sequence of an RNA molecule....

, which forms peptide links between adjacent amino acids using tRNAs during the translation
Translation (genetics)
In molecular biology and genetics, translation is the third stage of protein biosynthesis . In translation, messenger RNA produced by transcription is decoded by the ribosome to produce a specific amino acid chain, or polypeptide, that will later fold into an active protein...

 process of protein biosynthesis
Protein biosynthesis
Protein biosynthesis is the process in which cells build or manufacture proteins. The term is sometimes used to refer only to protein translation but more often it refers to a multi-step process, beginning with amino acid synthesis and transcription of nuclear DNA into messenger RNA, which is then...

.

Peptidyl transferase activity is carried out by the ribosome. Peptidyl transferase activity is not mediated by any ribosomal proteins but by ribosomal RNA (rRNA), a ribozyme. This RNA relic is the most significant piece of evidence supporting the RNA World hypothesis.
  • In Bacteria
    Bacteria
    Bacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...

    , the 50S (23S component) ribosome subunit contains the peptidyl transferase component and acts as a ribozyme.
  • In eukaryotic cells, the 60S (28S component) ribosome subunit contains the peptidyl transferase component and acts as the ribozyme.


Peptidyl transferases are not limited to translation, but there are relatively few enzymes with this function.

Antibiotic target

The following protein synthesis inhibitor
Protein synthesis inhibitor
A protein synthesis inhibitor is a substance that stops or slows the growth or proliferation of cells by disrupting the processes that lead directly to the generation of new proteins....

s target peptidyl transferase:
  • Chloramphenicol
    Chloramphenicol
    Chloramphenicol is a bacteriostatic antimicrobial that became available in 1949. It is considered a prototypical broad-spectrum antibiotic, alongside the tetracyclines, and as it is both cheap and easy to manufacture it is frequently found as a drug of choice in the third world.Chloramphenicol is...

     binds to A2451 and A2452 residues in the 23S rRNA of the ribosome and inhibits peptide bond
    Peptide bond
    This article is about the peptide link found within biological molecules, such as proteins. A similar article for synthetic molecules is being created...

     formation.
  • Pleuromutilin
    Pleuromutilin
    Pleuromutilin and its derivatives are antibacterial drugs that inhibit protein synthesis in bacteria by binding to the peptidyl transferase component of the 50S subunit of ribosomes....

    s also bind to peptidyl transferase.
  • Macrolide
    Macrolide
    The macrolides are a group of drugs whose activity stems from the presence of a macrolide ring, a large macrocyclic lactone ring to which one or more deoxy sugars, usually cladinose and desosamine, may be attached. The lactone rings are usually 14-, 15-, or 16-membered...

     antibiotics are thought to inhibit peptidyl transferase, in addition to inhibiting ribosomal translocation
    Ribosomal translocation
    Ribosomal translocation is a step in both:*Eukaryotic elongation and*Prokaryotic elongation, during translation of messenger RNA into proteins...

    .
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