0000000000848954

AUTHOR

Nina Morgner

showing 3 related works from this author

A Janus-Faced IM30 Ring Involved in Thylakoid Membrane Fusion Is Assembled from IM30 Tetramers.

2017

Summary Biogenesis and dynamics of thylakoid membranes likely involves membrane fusion events. Membrane attachment of the inner membrane-associated protein of 30 kDa (IM30) affects the structure of the lipid bilayer, finally resulting in membrane fusion. Yet, how IM30 triggers membrane fusion is largely unclear. IM30 monomers pre-assemble into stable tetrameric building blocks, which further align to form oligomeric ring structures, and differently sized IM30 rings bind to membranes. Based on a 3D reconstruction of IM30 rings, we locate the IM30 loop 2 region at the bottom of the ring and show intact membrane binding but missing fusogenic activity of loop 2 mutants. However, helix 7, which …

0301 basic medicineModels MolecularChemistryPeripheral membrane proteinLipid bilayer fusionBiological membraneMembrane FusionThylakoidsTransmembrane protein03 medical and health sciencesCrystallographyChloroplast Proteins030104 developmental biologyMembraneStructural BiologyMembrane biogenesisLiposomesBiophysicsProtein MultimerizationLipid bilayerMolecular BiologyIntegral membrane proteinProtein BindingStructure (London, England : 1993)
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Symmetry and Electronic Structure of Noble Metal Nanoparticles and the Role of Relativity

2004

High resolution photoelectron spectra of cold mass selected Cu_n-, Ag_n- and Au_n- with n =53-58 have been measured at a photon energy of 6.42 eV. The observed electron density of states is not the expected simple electron shell structure, but seems to be strongly influenced by electron-lattice interactions. Only Cu55- and Ag55- exhibit highly degenerate states. This is a direct consequence of their icosahedral symmetry, as is confirmed by density functional theory calculations. Neighboring sizes exhibit perturbed electronic structures, as they are formed by removal or addition of atoms to the icosahedron and therefore have lower symmetries. Gold clusters in the same size range show complet…

PhysicsIcosahedral symmetryDegenerate energy levelsElectron shellGeneral Physics and AstronomyFOS: Physical sciencesElectronic structureSpectral lineCondensed Matter - Other Condensed MatterAb initio quantum chemistry methodsDensity of statesDensity functional theoryAtomic physicsOther Condensed Matter (cond-mat.other)
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Structure of the Human TRPML2 Ion Channel Extracytosolic/Lumenal Domain.

2019

Summary TRPML2 is the least structurally characterized mammalian transient receptor potential mucolipin ion channel. The TRPML family hallmark is a large extracytosolic/lumenal domain (ELD) between transmembrane helices S1 and S2. We present crystal structures of the tetrameric human TRPML2 ELD at pH 6.5 (2.0 A) and 4.5 (2.95 A), corresponding to the pH values in recycling endosomes and lysosomes. Isothermal titration calorimetry shows Ca2+ binding to the highly acidic central pre-pore loop which is abrogated at low pH, in line with a pH-dependent channel regulation model. Small angle X-ray scattering confirms the ELD dimensions in solution. Changes in pH or Ca2+ concentration do not affect…

Models Molecular0303 health sciencesBinding SitesTRPMLEndosomeChemistrySmall-angle X-ray scatteringProtein Conformation030302 biochemistry & molecular biologyIsothermal titration calorimetryHydrogen-Ion ConcentrationCrystallography X-Ray03 medical and health sciencesTransient receptor potential channelTransmembrane domainTransient Receptor Potential ChannelsProtein DomainsStructural BiologyBiophysicsHumansCalciumMolecular BiologyProtein secondary structureIon channel030304 developmental biologyStructure (London, England : 1993)
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