The structure of the antibiotic resistance methyltransferase, NpmA, bound to the small ribosomal subunit has been featured in the Protein Data Bank's Molecule of the Month series. This structure, reported in the Proceedings of the National Academies of Science by Dunkle et al. in 2014, revealed specific ribosomal RNA helices are recognized by NpmA in a sequence-independent manner to direct enzyme specificity. Once bound to the ribosome, NpmA methylates a site in ribosomal RNA that blocks aminoglycoside binding. Bacteria expressing NpmA are therefore resistant to aminoglycoside antibiotics.
The Molecule of the Month series informs readers about molecular structures within the PDB and how these structures contribute to improving human health. The October 2018 entry in this series shows how molecular structures reveal the binding site and mechanism of action for aminoglycoside antibiotics and how bacteria become resistant.