Related Experiment Video

Updated: Jul 19, 2026

Analysis of Translation Initiation During Stress Conditions by Polysome Profiling
10:59

Analysis of Translation Initiation During Stress Conditions by Polysome Profiling

Published on: May 19, 2014

Inhibition of antiassociation activity of translation initiation factor 3 by paromomycin

Go Hirokawa1, Hideko Kaji, Akira Kaji

  • 1Department of Biochemistry and Molecular Biology, Jefferson Medical College, Thomas Jefferson University, 1020 Locust Street, JAH 456A, Philadelphia, PA 19107, USA.

Antimicrobial Agents and Chemotherapy
|November 8, 2006
PubMed

Insights

Paromomycin antibiotic disrupts bacterial ribosome assembly by preventing initiation factor 3 (IF3) from dissociating ribosomal subunits. This stabilization of 70S ribosomes contributes to paromomycin's inhibitory effects.

Area of Science:

  • Molecular Biology
  • Microbiology
  • Biochemistry

Background:

  • Ribosome biogenesis is crucial for protein synthesis in bacteria.
  • Initiation factor 3 (IF3) plays a key role in regulating ribosomal subunit association and dissociation.
  • Paromomycin is an aminoglycoside antibiotic that inhibits bacterial protein synthesis.

Purpose of the Study:

  • To investigate the effect of paromomycin on the interaction between ribosomal subunits.
  • To elucidate the mechanism by which paromomycin affects the function of initiation factor 3 (IF3).

Main Methods:

  • Studying the antiassociation activity of IF3 in the presence of paromomycin.
  • Observing the association of ribosomal subunits to form 70S ribosomes under varying conditions.
  • Analyzing the binding and expulsion of IF3 from 30S ribosomal subunits.

Main Results:

  • Paromomycin inhibited the antiassociation activity of IF3.
  • Paromomycin promoted the association of ribosomal subunits into 70S ribosomes, even with low Mg(2+) concentrations.
  • IF3 bound to 30S subunits was expelled upon paromomycin-induced 70S ribosome formation.

Conclusions:

  • Paromomycin stabilizes 70S ribosome formation.
  • This stabilization mechanism contributes to paromomycin's inhibition of translocation and ribosome recycling.
  • Paromomycin's effects on ribosome dynamics offer insights into its antibiotic action.

More Related Videos

Isolation of Translating Ribosomes Containing Peptidyl-tRNAs for Functional and Structural Analyses11:19

Isolation of Translating Ribosomes Containing Peptidyl-tRNAs for Functional and Structural Analyses

Published on: February 25, 2011

Quantitative Immunofluorescence to Measure Global Localized Translation09:13

Quantitative Immunofluorescence to Measure Global Localized Translation

Published on: August 22, 2017

Related Concept Videos

Inhibitors of Bacterial Protein Synthesis01:25

Inhibitors of Bacterial Protein Synthesis

Aminoglycosides constitute a highly potent class of bactericidal antibiotics that exert their antimicrobial effects by targeting the bacterial ribosome, specifically disrupting protein synthesis. These polycationic molecules consist of amino-modified sugars linked via glycosidic bonds to an aminocyclitol core such as 2-deoxystreptamine or streptamine. Their strong positive charges facilitate tight binding to the negatively charged phosphate backbone of ribosomal RNA (rRNA), primarily at the 16S...
Eukaryotic Transcription Inhibitors01:52

Eukaryotic Transcription Inhibitors

Certain biochemical processes, such as embryonic development and cell growth regulation, depend on the repression of specific genes. DNA binding proteins known as eukaryotic transcription inhibitors regulate the repression of gene expression in eukaryotes. The presence of these inhibitors at the required location and time in the cell is triggered by the presence of hormones and additional signals from other cells.
Eukaryotic transcription inhibitors usually contain two distinct domains, a DNA...
Inhibitors of Viral Protein Synthesis01:30

Inhibitors of Viral Protein Synthesis

Protein synthesis is indispensable for viral replication, as viruses lack the cellular machinery required for this process and must hijack the host's translational apparatus. In response, host cells deploy a critical innate immune defense involving interferons, specialized cytokines that play a central role in inhibiting viral propagation.Upon viral detection, infected cells release interferons that bind to receptors on adjacent uninfected cells, activating the JAK-STAT signaling pathway and...
Initiation of Translation02:33

Initiation of Translation

Initiating translation is complex because it involves multiple molecules. Initiator tRNA, ribosomal subunits, and eukaryotic initiation factors (eIFs) are all required to assemble on the initiation codon of mRNA. This process consists of several steps that are mediated by different eIFs.
First, the initiator tRNA must be selected from the pool of elongator tRNAs by eukaryotic initiation factor 2 (eIF2). The initiator tRNA (Met-tRNAi) has conserved sequence elements including modified bases at...
Initiation of Translation02:33

Initiation of Translation

Initiating translation is complex because it involves multiple molecules. Initiator tRNA, ribosomal subunits, and eukaryotic initiation factors (eIFs) are all required to assemble on the initiation codon of mRNA. This process consists of several steps that are mediated by different eIFs.
First, the initiator tRNA must be selected from the pool of elongator tRNAs by eukaryotic initiation factor 2 (eIF2). The initiator tRNA (Met-tRNAi) has conserved sequence elements including modified bases at...
Transcription Attenuation in Prokaryotes02:42

Transcription Attenuation in Prokaryotes

Transcriptional attenuation occurs when RNA transcription is prematurely terminated due to the formation of a terminator mRNA hairpin structure.  Bacteria use these hairpins to regulate the transcription process and control the synthesis of several amino acids including histidine, lysine, threonine, and phenylalanine. Transcription attenuation takes place in the non-coding regions of mRNA.
There are several different mechanisms used to attenuate transcription. In ribosome mediated...