Metals

  • Article
    | Open Access

    The mechanisms involved in SLC4-mediated ion transport are still under debate. Here, the authors present a cryoEM structure of the Sodium-driven Chloride/Bicarbonate Exchanger NDCBE, which - together with computational modeling and mutagenesis - reveals molecular determinants of ion transport by SLC4.

    • Weiguang Wang
    • , Kirill Tsirulnikov
    •  & Ira Kurtz
  • Article
    | Open Access

    CNNM/CorB proteins are a conserved family of membrane proteins associated with Mg2+ transport. Here, structures of an archaeal CorB protein in apo state and with Mg2+-ATP bound and accompanying biophysical experiments suggest direct Mg2+ transport by CorB proteins.

    • Yu Seby Chen
    • , Guennadi Kozlov
    •  & Kalle Gehring
  • Article
    | Open Access

    Filamentous cable bacteria conduct electrical currents over centimeter distances through fibers embedded in their cell envelope. Here, Boschker et al. show that the fibers consist of a conductive core containing nickel proteins that is surrounded by an insulating protein shell.

    • Henricus T. S. Boschker
    • , Perran L. M. Cook
    •  & Filip J. R. Meysman
  • Article
    | Open Access

    Silver (Ag) has been used as an antimicrobial agent since a long time, but its molecular mechanism of action was not elucidated due to technical challenges. Here, the authors develop a mass spectrometric approach to identify the Ag-proteome in Staphylococcus aureus, and capture a molecular snapshot of the dynamic bactericidal mode of action of Ag through targeting multiple biological pathways.

    • Haibo Wang
    • , Minji Wang
    •  & Hongzhe Sun
  • Article
    | Open Access

    Iron is an essential plant nutrient that is poorly bioavailable in alkaline soils, resulting in reduced agricultural productivity. Here, the authors report the synthesis of stable and cheap iron-chelator, proline-2’-deoxymugineic acid (PDMA), and demonstrate its utility as potential fertilizer.

    • Motofumi Suzuki
    • , Atsumi Urabe
    •  & Kosuke Namba
  • Article
    | Open Access

    The connection between metal binding to proteins and availabilities of different metals in cells has been unclear. Here, the authors report a metalation-calculator that takes into account competition between metals and their variable accessibility, and thereby elucidate in vivo metal occupancies of three different proteins, CobW, YeiR and YjiA.

    • Tessa R. Young
    • , Maria Alessandra Martini
    •  & Nigel J. Robinson
  • Article
    | Open Access

    The human AAA+protein p97 plays an important role in cellular protein homeostasis. Here, the authors use cryo-EM to obtain further insights into how p97 interacts with its co-factor Npl4 and they observe three distinct conformational states of Npl4 in complex with human p97, which suggests that a seesaw motion is essential for the unfolding activity of the p97 complex.

    • Man Pan
    • , Qingyun Zheng
    •  & Minglei Zhao
  • Article
    | Open Access

    Heme biosynthesis depends on iron-sulfur (Fe-S) cluster biogenesis but the molecular connection between these pathways is not fully understood. Here, the authors show that the heme biosynthesis enzyme ALAD contains an Fe-S cluster, disruption of which reduces ALAD activity and heme production in human cells.

    • Gang Liu
    • , Debangsu Sil
    •  & Tracey Ann Rouault
  • Article
    | Open Access

    Photosynthetic formation of manganese (Mn) oxides from dissolved Mn ions was proposed to occur in ancestral photosystems before oxygenic photosynthesis evolved. Here, the authors provide evidence for this hypothesis by showing that photosystem II devoid of the Mn cluster oxidises Mn ions leading to formation of Mn-oxide nanoparticles.

    • Petko Chernev
    • , Sophie Fischer
    •  & Holger Dau
  • Article
    | Open Access

    Glutaredoxins are a family of essential enzymes divided into two major classes with either a CGFS or a CxxC active site, of which only the latter exhibits oxidoreductase activity. Here the authors address the structural basis for the functional difference between the two classes of glutaredoxins.

    • Daniel Trnka
    • , Anna D. Engelke
    •  & Christopher Horst Lillig
  • Article
    | Open Access

    Many metalloenzymes are highly specific for their cognate metal ion but the molecular principles underlying this specificity often remain unclear. Here, the authors characterize the structural and biochemical basis for the different metal specificity of two evolutionarily related superoxide dismutases.

    • Anna Barwinska-Sendra
    • , Yuritzi M. Garcia
    •  & Kevin J. Waldron
  • Article
    | Open Access

    Mobile group II introns function as ribozymes to splice and reinsert themselves into DNA, thereby colonizing new genomic regions. Here the authors use single-molecule FRET and molecular dynamics simulations to reveal a structural link between metal ion induced kinetic heterogeneity and the sugar puckers at the exon-intron binding interface.

    • Fabio D. Steffen
    • , Mokrane Khier
    •  & Roland K. O. Sigel
  • Article
    | Open Access

    The mechanism of iron-sulfur (Fe-S) cluster biosynthesis is not fully understood. Here, the authors develop a physiologically relevant in vitro model of Fe-S cluster assembly, allowing them to elucidate the sequence of Fe-S cluster synthesis along with the respective roles of ferredoxin-2 and frataxin.

    • Sylvain Gervason
    • , Djabir Larkem
    •  & Benoit D’Autréaux
  • Article
    | Open Access

    Altered iron homeostasis resulting in excessive oxidative stress has been implicated in smoke-induced lung diseases. Here the authors show that ferroptosis of lung epithelial cells, potentially resulting from excessive ferritinophagy, is involved in the pathogenesis of COPD.

    • Masahiro Yoshida
    • , Shunsuke Minagawa
    •  & Kazuyoshi Kuwano
  • Article
    | Open Access

    Metal ions play essential roles in myriads of biological processes, from catalytic co-factors to supporting protein and nucleic acid structures. Here the authors use long-wavelength X-ray diffraction to locate hundreds of potassium ions taking part in the formation of rRNA tertiary structure, mediating rRNA–protein interactions and supporting ribosomal protein structures and function.

    • Alexey Rozov
    • , Iskander Khusainov
    •  & Gulnara Yusupova
  • Article
    | Open Access

    In many AMPylating FIC proteins a structurally conserved glutamate represses AMPylation. Here, the authors show that this glutamate supports deAMPylation in Enterococcus faecalis FIC (EfFIC), and that EfFIC switches from AMPylation to deAMPylation by binding Ca2+ at distinct sites.

    • Simon Veyron
    • , Giulia Oliva
    •  & Jacqueline Cherfils
  • Article
    | Open Access

    There are only few MRI-compatible calcium reporters and they are limited to measuring extracellular calcium levels. Here the authors develop and validate a cell-permeable, manganese-based paramagnetic MRI contrast agent that enables monitoring intracellular calcium signals in vivo in the rat brain.

    • Ali Barandov
    • , Benjamin B. Bartelle
    •  & Alan Jasanoff
  • Article
    | Open Access

    Ferroportin (Fpn) is essential for mammalian iron homeostasis as it exports iron from cells into blood circulation, but the molecular mechanisms of Fpn-mediated iron transport remain obscure. Here the authors use biophysical approaches to reveal that Ca2+ is a required cofactor for Fpn transport activity.

    • Chandrika N. Deshpande
    • , T. Alex Ruwe
    •  & Mika Jormakka
  • Article
    | Open Access

    Fe/S clusters are synthesized by the mitochondrial iron-sulfur cluster assembly (ISC) machinery. Here the authors combine crystallography and small angle X-ray scattering measurements to structurally characterize the core ISC complex and give functional insights into eukaryotic Fe/S cluster synthesis.

    • Michal T. Boniecki
    • , Sven A. Freibert
    •  & Miroslaw Cygler
  • Article
    | Open Access

    Hepcidin controls systemic iron levels by inhibiting intestinal iron absorption and iron recycling. Here, Pasricha et al. demonstrate that the hepcidin-chromatin locus displays HDAC3-mediated reversible epigenetic modifications during both erythropoiesis and iron deficiency.

    • Sant-Rayn Pasricha
    • , Pei Jin Lim
    •  & Hal Drakesmith
  • Article
    | Open Access

    The biosynthesis of iron-sulfur clusters in anaerobic organisms has not been extensively investigated. Here, the authors identify and characterize a multi-subunit protein that stores iron and sulfur in thioferrate for the assembly of the clusters inPyrococcus furiosus.

    • Brian J. Vaccaro
    • , Sonya M. Clarkson
    •  & Michael W. W. Adams
  • Article
    | Open Access

    The mitochondrial proteins ISCA1 and ISCA2 form a complex that is involved in the biogenesis of Fe–S clusters. Here the authors report that ISCA1 and ISCA2 interact differently with proteins of the Fe–S machinery and that under certain conditions, ISCA2 seems dispensable for Fe–S biogenesis.

    • Lena Kristina Beilschmidt
    • , Sandrine Ollagnier de Choudens
    •  & Alain Martelli
  • Article
    | Open Access

    Iron overload can be either hereditary or acquired via transfusions, and current treatments include the use of iron chelators that have adverse effects in some patients. Here the authors modify siderocalin to enhance iron excretion in urine, and demonstrate therapeutic efficacy in iron overload mouse models.

    • Jonathan Barasch
    • , Maria Hollmen
    •  & Andong Qiu
  • Article
    | Open Access

    The calcium-regulated gelsolin family of actin-binding proteins includes adseverin. Here, the authors report the X-ray crystal structure of the N-terminal portion of adseverin and use small-angle scattering and molecular dynamics simulations to examine the calcium-dependent function of this protein.

    • Sakesit Chumnarnsilpa
    • , Robert C. Robinson
    •  & Cedric Leyrat
  • Article
    | Open Access

    The molecular basis for the high toxicity of cadmium is unclear. Here, Begg et al. use the bacterium Streptococcus pneumoniaeas a model system, and show that cadmium uptake increases sensitivity to oxidative stress by reducing intracellular concentrations of manganese and zinc through different mechanisms.

    • Stephanie L. Begg
    • , Bart A. Eijkelkamp
    •  & Christopher A. McDevitt
  • Article
    | Open Access

    Magnesium is an essential element of the diet and is a cofactor for many enzymes. In this study, the channel kinase TRPM7 is shown to be essential for magnesium homeostasis, and heterozygous mice lacking the kinase domain show a defect in absorption of magnesium from the diet.

    • Lillia V. Ryazanova
    • , Lusliany J. Rondon
    •  & Alexey G. Ryazanov
  • Article |

    Electrons in metals at extremely high magnetic fields show interesting quantum structures. The authors measure the angle-dependent Nernst effect with high precision and show that, for bismuth, Coulomb interactions between the electrons become important in this ultraquantum regime.

    • Huan Yang
    • , Benoît Fauqué
    •  & Kamran Behnia