Structure and ion-release mechanism of PIB-4-type ATPases
- University of Copenhagen, Denmark
- Umeå University, Sweden
- Lund University, Sweden
- The University of Texas at Dallas, United States
- University of Cambridge, United Kingdom
Abstract
Transition metals, such as zinc, are essential micronutrients in all organisms, but also highly toxic in excessive amounts. Heavy-metal transporting P-type (PIB) ATPases are crucial for homeostasis, conferring cellular detoxification and redistribution through transport of these ions across cellular membranes. No structural information is available for the PIB-4-ATPases, the subclass with the broadest cargo scope, and hence even their topology remains elusive. Here we present structures and complementary functional analyses of an archetypal PIB‑4‑ATPase, sCoaT from Sulfitobacter sp. NAS14-1. The data disclose the architecture, devoid of classical so-called heavy metal binding domains, and provides fundamentally new insights into the mechanism and diversity of heavy-metal transporters. We reveal several novel P-type ATPase features, including a dual role in heavy-metal release and as an internal counter ion of an invariant histidine. We also establish that the turn-over of PIB‑ATPases is potassium independent, contrasting to many other P-type ATPases. Combined with new inhibitory compounds, our results open up for efforts in e.g. drug discovery, since PIB-4-ATPases function as virulence factors in many pathogens.
Data availability
Atomic coordinates and structure factors for the sCoaT AlF4-- and BeF3--stabilized crystal structures have been deposited at the Protein Data Bank (PDB) under accession codes 7QBZ and 7QC0.
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Structure and ion-release mechanism of PIB-4-type ATPasesProtein Data Bank, 7QBZ.
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Structure and ion-release mechanism of PIB-4-type ATPasesProtein Data Bank, 7QC0.
Article and author information
Author details
Funding
Novo Nordisk Fonden (NNF18SA0034956)
- Christina Grønberg
Lundbeckfonden (R313-2019-774,R218-2016-1548,R133-A12689)
- Pontus Gourdon
Knut och Alice Wallenbergs Stiftelse (2020.0194,2015.0131)
- Pontus Gourdon
Carlsbergfondet (CF15-0542,2013_01_0641)
- Pontus Gourdon
Novo Nordisk Fonden (NNF13OC0007471)
- Pontus Gourdon
Brodrene Hartmann (A29519)
- Pontus Gourdon
Agnes og Poul Friis Fond
- Pontus Gourdon
Augustinus Fonden (16-1992)
- Pontus Gourdon
Crafoord (20180652,20170818)
- Pontus Gourdon
Per-Eric and Ulla Schyberg (38267)
- Pontus Gourdon
Swedish Research Council (2016-04474)
- Pontus Gourdon
The memorial foundation of manufacturer Vilhelm Pedersen and wife - and the Aarhus Wilson consortium
- Christina Grønberg
The Independent Research Fund Denmark (9039-00273A)
- Pontus Gourdon
China Scholarship Council
- Qiaoxia Hu
Carl Tryggers Stiftelse för Vetenskaplig Forskning (CTS 17:22)
- Dhani Ram Mahato
Swedish Research Council Starting Grant (2016-03610)
- Magnus Andersson
Robert A. Welke Cancer Research Foundation (AT-1935-20170325 and AT-2073-20210327)
- Gabriele Meloni
National Institute of General Medical Sciences (R35GM128704))
- Gabriele Meloni
National Science Foundation (CHE- 2045984)
- Gabriele Meloni
Swedish Heart-Lung Foundation (20200378)
- Gabriela Godaly
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Copyright
© 2021, Grønberg et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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Structure and ion-release mechanism of PIB-4-type ATPases
eLife 10:e73124.
https://doi.org/10.7554/eLife.73124
Further reading
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- Biochemistry and Chemical Biology
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Teichoic acids (TA) are linear phospho-saccharidic polymers and important constituents of the cell envelope of Gram-positive bacteria, either bound to the peptidoglycan as wall teichoic acids (WTA) or to the membrane as lipoteichoic acids (LTA). The composition of TA varies greatly but the presence of both WTA and LTA is highly conserved, hinting at an underlying fundamental function that is distinct from their specific roles in diverse organisms. We report the observation of a periplasmic space in Streptococcus pneumoniae by cryo-electron microscopy of vitreous sections. The thickness and appearance of this region change upon deletion of genes involved in the attachment of TA, supporting their role in the maintenance of a periplasmic space in Gram-positive bacteria as a possible universal function. Consequences of these mutations were further examined by super-resolved microscopy, following metabolic labeling and fluorophore coupling by click chemistry. This novel labeling method also enabled in-gel analysis of cell fractions. With this approach, we were able to titrate the actual amount of TA per cell and to determine the ratio of WTA to LTA. In addition, we followed the change of TA length during growth phases, and discovered that a mutant devoid of LTA accumulates the membrane-bound polymerized TA precursor.
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