Metalloproteins

  • Article
    | Open Access

    Various strategies to assemble protein building blocks into one-, two- and three-dimensional hierarchical nanostructures were described, but controlling the transformation between those different assemblies is largely uninvestigated. Here, the authors describe a protein interface redesign strategy and use it for the self-assembly transformation of dimeric building blocks from hollow protein nanocage to filament, nanorod and nanoribbon.

    • Xiaorong Zhang
    • , Yu Liu
    •  & Guanghua 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

    The sulfur-reducing enzyme MBS and the hydrogen-gas evolving MBH are the evolutionary link between the ancestor Mrp antiporter and the mitochondrial respiratory complex I. Here, the authors characterise MBS from the hyperthermophilic archaeon Pyrococcus furiosus, solve its cryo-EM structure and discuss the structural evolution from Mrp to MBH and MBS and to the modern-day complex I.

    • Hongjun Yu
    • , Dominik K. Haja
    •  & Michael W. W. Adams
  • Article
    | Open Access

    Metalloenzymes often show different catalytic activities in the presence of non-native metal ions. Here, the authors report structures of carbonic anhydrase bound to zinc and several other metal ions and demonstrate that metal ion coordination geometries directly impact catalytic activity of the enzyme.

    • Jin Kyun Kim
    • , Cheol Lee
    •  & Chae Un Kim
  • 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

    Understanding enzyme active sites can elucidate fundamental enzymatic reaction pathways and inform designs for synthetic catalysts. Here, authors employ operando X-ray absorption spectroelectrochemistry to assess copper ions in bilirubin oxidase during oxygen reduction electrocatalysis.

    • Lucyano J. A. Macedo
    • , Ayaz Hassan
    •  & Frank N. Crespilho
  • Article
    | Open Access

    Iron is essential for growth of Mycobacterium tuberculosis, but most of the iron in the human body is stored in heme within hemoglobin. Here, Mitra et al. identify two heme uptake mechanisms in M. tuberculosis, one dependent on the inner-membrane Dpp importer and the other dependent on host albumin.

    • Avishek Mitra
    • , Ying-Hui Ko
    •  & Michael Niederweis
  • Article
    | Open Access

    Metallo-β-lactamases (MBLs) confer resistance to carbapenem antibiotics. Here, López et al. show that the host range of MBLs depends on the efficiency of MBL signal peptide processing and secretion into outer membrane vesicles, which affects bacterial fitness.

    • Carolina López
    • , Juan A. Ayala
    •  & Alejandro J. Vila
  • 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

    The activity of the membrane-bound enzyme pMMO depends on copper but the location of the copper centers is still under debate. Here, the authors reconstitute pMMO in nanodiscs and use native top-down MS to localize its copper centers, providing insights into which sites are essential for activity.

    • Soo Y. Ro
    • , Luis F. Schachner
    •  & Amy C. Rosenzweig
  • Article
    | Open Access

    Studying the electronic structures and spin transitions of synthetic heme analogs is crucial to advancing our understanding of heme enzyme mechanisms. Here the authors show that a Co(II) porphyrin complex undergoes an unexpected spin state transition upon deprotonation of its axial imidazole ligand.

    • Jianping Zhao
    • , Qian Peng
    •  & Jianfeng Li
  • Article
    | Open Access

    The human transferrin receptor 1 (CD71) is a transmembrane protein responsible for iron uptake. Here the authors present the 3.9 Å resolution cryo-EM structure of the CD71 ectodomain-human ferritin (H-Ft) complex and find that H-Ft binds a CD71 region different from the transferrin one that overlaps with the surface recognized by select pathogens.

    • Linda Celeste Montemiglio
    • , Claudia Testi
    •  & Beatrice Vallone
  • Article
    | Open Access

    The diheme enzyme MauG forms a bis-Fe(IV) state. Here the authors identify and determine the structure of BthA, a diheme peroxidase conserved in all Burkholderia and show that BthA also forms a bis-Fe(IV) species but mechanistically differs from MauG by combining magnetic resonance, near-IR and Mössbauer spectroscopies and electrochemical methods.

    • Kimberly Rizzolo
    • , Steven E. Cohen
    •  & Sean J. Elliott
  • Article
    | Open Access

    Tetrathiomolybdate (TM) and Cu-ATPases, e.g. Wilson (WLN) protein, affect the efficacy of common anticancer drug cisplatin. Here, the authors show that TM generates a protein dimer with a WLN domain by expelling copper and provide insight into the synergy of TM and cisplatin in cancer chemotherapy.

    • Tiantian Fang
    • , Wanbiao Chen
    •  & Yangzhong Liu
  • Article
    | Open Access

    Marine woodborers can digest woody biomass without the help of gut microbiota but the mechanism has remained unclear. Here, the authors provide evidence that the woodborer’s respiratory protein hemocyanin plays a central role in wood digestion and may offer a route toward biorefining of woody plant biomass.

    • Katrin Besser
    • , Graham P. Malyon
    •  & Simon J. McQueen-Mason
  • Article
    | Open Access

    Myoglobin bound to carbon monoxide undergoes an ultrafast light-induced reaction, which ends up in a photolyzed carbon monoxide and a spin transition of the iron center. Here, the authors employ quantum wavepacket dynamics to show that photolysis precedes the spin transition, a mechanism dominated by strong electron-nuclear couplings.

    • Konstantin Falahati
    • , Hiroyuki Tamura
    •  & Miquel Huix-Rotllant
  • Article
    | Open Access

    Methane- and ammonia-oxidizing bacteria use the integral membrane, copper-dependent enzymes particulate methane monooxygenase (pMMO) and ammonia monooxygenase (AMO) to oxidize methane and ammonia. Here the authors structurally characterize the copper-binding protein PmoD, which contains an unusual CuA site and their genetic analyses strongly support a pMMO and AMO related function of PmoD.

    • Oriana S. Fisher
    • , Grace E. Kenney
    •  & Amy C. Rosenzweig
  • Article
    | Open Access

    Cytochrome c oxidase (CytcO) is the last enzyme of the electron transport chain, but how the electrochemical membrane potential affects CytcO is unclear. Here the authors show that proton uptake to the catalytic site of CytcO and presumably proton translocation was impaired by the potential, but electron transfer was not affected.

    • Markus L. Björck
    •  & Peter Brzezinski
  • Article
    | Open Access

    NifB is a key enzyme in the biosynthesis pathway of the nitrogenase FeMo cofactor. Here, the authors investigate the maturation of its iron-sulfur clusters by EPR and biochemical analyses, showing how individual precursor clusters participate in the formation of the final iron-sulfur cluster.

    • Lee A. Rettberg
    • , Jarett Wilcoxen
    •  & Yilin Hu
  • Article
    | Open Access

    Artificial compartments have been expressed in prokaryotes and yeast, but similar capabilities have been missing for mammalian cell engineering. Here the authors use bacterial encapsulins to engineer genetically controlled multifunctional orthogonal compartments in mammalian cells.

    • Felix Sigmund
    • , Christoph Massner
    •  & Gil G. Westmeyer
  • Article
    | Open Access

    Despite being highly toxic, carbon monoxide (CO) is also essential as an intracellular signalling molecule, but CO-dependent signalling is poorly understood. Here, authors employ spectroscopic and electrophysiology methods and find that CO activates KATP channels via SUR2A, a heme-regulated receptor.

    • Sofia M. Kapetanaki
    • , Mark J. Burton
    •  & Emma Raven
  • Article
    | Open Access

    Mycobacterium tuberculosis WhiB1 is a DNA-binding protein with a NO sensitive [4Fe-4S] cluster. Here the authors present the NMR structure of WhiB1 and suggest how loss of the iron-sulfur cluster through nitrosylation affects WhiB1 DNA binding and leads to transcriptional reprogramming.

    • Bassam K. Kudhair
    • , Andrea M. Hounslow
    •  & Jeffrey Green
  • Article
    | Open Access

    Bacteria possess transcription factors whose DNA-binding activity is altered upon binding to specific metals, but the binding of metals is not specific in vitro. Here, Osman et al. show that tight regulation of buffered intracellular metal concentrations is a prerequisite for metal specificity.

    • Deenah Osman
    • , Andrew W. Foster
    •  & Nigel J. Robinson
  • Article
    | Open Access

    Significant challenges exist for structural characterization of enzymes responsible for biomineralization. Here the authors show that native mass spectrometry and high resolution electron microscopy can define the subunit topology and copper binding of a manganese oxidizing complex, and describe early stage formation of its mineral products

    • Christine A. Romano
    • , Mowei Zhou
    •  & Bradley M. Tebo
  • Article
    | Open Access

    Carbapenem-resistant bacteria pose a major health threat by expressing metallo-β-lactamases (MβLs), enzymes able to hydrolyse these life-saving drugs. Here the authors use biophysical and computational methods and show that different MβLs share the same reaction mechanism, suggesting new strategies for drug design.

    • María-Natalia Lisa
    • , Antonela R. Palacios
    •  & Alejandro J. Vila
  • 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

    Proteins can template the synthesis of inorganic nanoparticles, but the formation mechanisms remain vague. Here, the authors directly observe, through a sequence of X-ray crystal structures, the stages of gold sub-nanocluster growth within the confined environment of a ferritin cage.

    • Basudev Maity
    • , Satoshi Abe
    •  & Takafumi Ueno
  • Article
    | Open Access

    Nitrogenases reduce inorganic nitrogen to organic ammonia in a crucial step of the nitrogen cycle. Here the authors show that the vanadium-nitrogenase ofAzotobacter vinelandii can also catalyse the in vivoconversion of carbon monoxide to hydrocarbons in a secondary non-biosynthetic pathway.

    • Johannes G. Rebelein
    • , Chi Chung Lee
    •  & Markus W. Ribbe
  • Article
    | Open Access

    High levels of homocysteine in cells are linked to pathological states. Here, the authors report that homocysteine inactivates catalase by modifying the heme group, impairing cellular redox homeostasis, and show that this modification occurs in cancer cells and in a cellular model of Parkinson’s disease.

    • Dominique Padovani
    • , Assia Hessani
    •  & Isabelle Artaud
  • Article
    | Open Access

    Lytic polysaccharide monooxygenases are proteins involved in the degradation of plant biomass and are promising biotechnological tools for biofuel production. Here, the authors show that their catalytic activity is significantly boosted when they are combined with photopigments and exposed to light.

    • D. Cannella
    • , K. B. Möllers
    •  & C. Felby
  • Article
    | Open Access

    The [Mo:7Fe:9S:C] iron-molybdenum cofactor (FeMoco) of nitrogenase is a large metal cluster with an important role in biological nitrogen fixation. Here, the authors use spatially resolved refinement of the anomalous scattering contributions of the iron atoms to determine the resting-state electron distribution of FeMoco.

    • Thomas Spatzal
    • , Julia Schlesier
    •  & Oliver Einsle
  • Article
    | Open Access

    Artificial metalloenzymes (ArMs) have the potential to improve transition metal reactivity in complex media. Here, the authors link a dirhodium catalyst to a prolyl oligopeptidase to create an ArM that catalyzes enantioselective olefin cyclopropanation in aqueous solution.

    • Poonam Srivastava
    • , Hao Yang
    •  & Jared C. Lewis
  • Article
    | Open Access

    The investigation of the chemical reactivity of metal centres in metalloproteins in aqueous solution is challenging. Here, the authors demonstrate the use of single molecule force spectroscopy to study the chemical reactivity of the iron-sulfur centre in rubredoxin in aqueous solution.

    • Peng Zheng
    • , Guilherme M. Arantes
    •  & Hongbin Li
  • Article
    | Open Access

    Carotenes are naturally abundant, widely studied unsaturated hydrocarbon pigments but their metal-binding ability has been virtually unexplored. Here, the authors demonstrate that they can be used to reversibly assemble and align homo- and hetero-metallic decanuclear chain complexes.

    • Shinnosuke Horiuchi
    • , Yuki Tachibana
    •  & Tetsuro Murahashi