Puromycin

Puromycin is an aminonucleoside antibiotic, derived from the Streptomyces alboniger bacterium, that causes premature chain termination during translation taking place in the ribosome. In molecular biology, puromycin is used in laboratories, among other things, to study protein synthesis.

Structure and properties

Puromycin is structurally similar to aminoacyl tRNA. It is taken up in the A site of the ribosome during translation, causes premature chain termination by acting as an analog of the 3'-end of tyrosyl tRNA. This property leads to the incorporation of puromycin into the nascent chain and the subsequent release of the polypeptide.

Uses

In molecular biology, puromycin is used to study protein synthesis. By incorporating itself into the growing protein chain, the formation of long proteins is prevented, allowing the study of their synthesis. Puromycin is also used as a selective agent in laboratory cultures. It kills all cells that have not been transformed with a resistance gene (pac gene).

Resistance

Resistance to puromycin is conferred by the pac gene, encoding a puromycin N-acetyl-transferase (PAC) that was found in a Streptomyces producer strain. This enzyme inactivates puromycin by transferring an acetyl group from acetyl coenzyme A to the primary amine of puromycin.

See also

• Aminonucleoside
• Antibiotic
• Streptomyces alboniger
• Translation (biology)
• Ribosome
• Aminoacyl tRNA
• Tyrosyl tRNA
• Molecular biology
• Protein synthesis
• Pac gene
• Puromycin N-acetyl-transferase

Puromycin

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  Puromycin skeletal structure
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  Puromycin 3D spacefill model