Klebsiella pneumoniae is a bacterial pathogen that is increasingly responsible for hospital-acquired pneumonia and sepsis. Progressive development of antibiotic resistance has led to higher mortality rates and creates a need for novel treatments. Because of the essential role that nucleotides play in many bacterial processes, enzymes involved in purine and pyrimidine metabolism and transport are ideal targets for the development of novel antibiotics. Herein we describe the structure of K. pneumoniae adenosine monophosphate nucleosidase (KpAmn), a purine salvage enzyme unique to bacteria, as determined by cryoelectron microscopy. The data detail a well conserved fold with a hexameric overall structure and clear density for the putative active site residues. Comparison to the crystal structures of homologous prokaryotic proteins confirms the presence of many of the conserved structural features of this protein yet reveals differences in distal loops in the absence of crystal contacts. This first cryo-EM structure of an Amn enzyme provides a basis for future structure-guided drug development and extends the accuracy of structural characterization of this family of proteins beyond this clinically relevant organism.
Bibliographical noteFunding Information:
This project has been funded in part with Federal funds from the National Institute of General Medical Science and National Institute of Allergy and Infectious Diseases, National Institutes of Health, Department of Health and Human Services, under grant number R35GM124898 and contract No. HHSN272201700059C, respectively. The funding agencies that supported this work had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. We thank Janarjan Bhandari for cryo-EM data collection. We would like to thank the entire SSGCID team for their support, especially the cloning and protein-production group at the University of Washington.
© 2022 Richardson et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
- Adenosine Monophosphate
- Anti-Bacterial Agents
- Cryoelectron Microscopy
- Klebsiella Infections/microbiology
- Klebsiella pneumoniae
- N-Glycosyl Hydrolases
PubMed: MeSH publication types
- Journal Article
- Research Support, N.I.H., Extramural