Inhibitors of protein synthesis; | Difference between prokaryotic and eukaryotic translation |

ZOOHCC - 501: Molecular Biology (Theory)

Unit 4: Translation 

Inhibitors of protein synthesis

Inhibitors of protein synthesis are molecules that interfere with the process of translation, which is the process by which genetic information in mRNA is used to synthesize a protein. Translation involves the coordinated action of many different proteins and RNA molecules, and inhibitors of protein synthesis can target various steps in this process.

There are several types of inhibitors of protein synthesis, including antibiotics and chemical inhibitors. Antibiotics are natural or synthetic compounds that are produced by microorganisms and are used to treat bacterial infections. Many antibiotics target bacterial protein synthesis by inhibiting specific steps in translation, such as the binding of aminoacyl-tRNA to the ribosome or the formation of peptide bonds between amino acids.

Chemical inhibitors are synthetic compounds that can be designed to specifically target different components of the translation machinery. They can be useful for studying the mechanisms of translation and for developing new drugs to treat bacterial infections. However, they can also have toxic effects on eukaryotic cells and can lead to unwanted side effects if used improperly.

In general, inhibitors of protein synthesis can be very effective in treating bacterial infections, but it is important to use them judiciously to avoid the development of antibiotic resistance and other negative consequences.

Explanation

Inhibitors of protein synthesis are molecules that interfere with the process of translation, the synthesis of proteins from mRNA. These inhibitors can be broadly classified into two categories:

Antibiotics: Antibiotics are natural or synthetic compounds that are produced by microorganisms and are used to treat bacterial infections. Many antibiotics target bacterial protein synthesis by inhibiting specific steps in translation. Examples of antibiotics that inhibit protein synthesis include:

Aminoglycosides: These antibiotics bind to the small subunit of the ribosome and interfere with the accuracy of translation.

Tetracyclines: These antibiotics bind to the small subunit of the ribosome and prevent the attachment of aminoacyl-tRNA to the ribosome.

Macrolides: These antibiotics bind to the large subunit of the ribosome and inhibit the elongation phase of translation.

Chemical inhibitors: Chemical inhibitors are synthetic compounds that can be designed to specifically target different components of the translation machinery. Examples of chemical inhibitors of protein synthesis include:

Cycloheximide: This chemical inhibitor binds to the large subunit of the ribosome and blocks the translocation step of translation.

Puromycin: This chemical inhibitor mimics an aminoacyl-tRNA and is incorporated into the growing polypeptide chain, causing premature termination of translation.

Chloramphenicol: This chemical inhibitor binds to the large subunit of the ribosome and inhibits the peptidyl transferase activity, preventing the formation of peptide bonds.

In general, inhibitors of protein synthesis can be very useful in studying the mechanisms of translation and in developing new drugs to treat bacterial infections. However, they can also have toxic effects on eukaryotic cells and can lead to unwanted side effects if used improperly.

Difference between prokaryotic and eukaryotic translation

Prokaryotic and eukaryotic cells differ in many ways, including the process of translation, which is the synthesis of proteins from mRNA. Here are 10 differences between prokaryotic and eukaryotic translation:

1. Ribosome size: Prokaryotic ribosomes are smaller (70S) than eukaryotic ribosomes (80S).
2. Initiation factors: Prokaryotes have fewer initiation factors than eukaryotes.
3. Shine-Dalgarno sequence: Prokaryotic mRNA contains a Shine-Dalgarno sequence that helps to initiate translation, whereas eukaryotic mRNA does not.
4. mRNA splicing: Eukaryotic mRNA may undergo splicing before translation, removing introns and joining exons. Prokaryotic mRNA does not undergo splicing.
5. Polycistronic mRNA: Prokaryotic mRNA can be polycistronic, meaning it codes for multiple proteins. Eukaryotic mRNA is typically monocistronic, coding for a single protein.
6. Post-translational modifications: Eukaryotic proteins may undergo post-translational modifications, such as glycosylation or phosphorylation, that are not found in prokaryotes.
7. Translation location: In prokaryotes, transcription and translation can occur simultaneously, whereas in eukaryotes, transcription occurs in the nucleus and translation occurs in the cytoplasm.
8. Elongation factors: Prokaryotes and eukaryotes use different elongation factors in the process of translation.
9. Antibiotics: Some antibiotics target prokaryotic ribosomes and can be used to treat bacterial infections. Eukaryotic ribosomes are not affected by these antibiotics.
10. Translation regulation: Eukaryotic translation is more tightly regulated than prokaryotic translation, with multiple mechanisms for controlling the rate of protein synthesis.