Molecule of the Month: Aminoglycoside Antibiotics and Resistance
Bacteria become resistant to aminoglycosides by destroying them or changing their target.
Seeing the Site(s)
Protecting the Site
Exploring the Structure
Aminoglycosides have several amine and hydroxyl groups that are essential for binding to RNA. To become resistant, bacteria commonly attack the drug itself, using dedicated aminoglycoside-modifying enzymes to add new chemical groups to these amines and hydroxyls so that the drug can no longer bind and perform its error-promoting function. The enzyme shown here adds a nucleotide to the drug. PDB entries 5cfs and 5cfu catch the enzyme before and after the reaction. To explore this enzyme in more detail, click on the image for an interactive JSmol.
Topics for Further Discussion
- In the search for new aminoglycosides, structural biologists have often studied just the target helix from the ribosome. For example, you can find many of these structures by searching for “neomycin” or “paromomycin” at the RCSB PDB site.
- Another way that bacteria become resistant to antibiotics is by pumping them out. To see some of these pumps, try searching for “efflux pump.”
- You can explore the structure and properties of aminoglycoside antibiotics themselves on their “Ligand” page, for example, for streptomycin or paromomycin.
October 2018, David Goodsellhttp://doi.org/10.2210/rcsb_pdb/mom_2018_10