title: High resolution structure and double electron-electron resonance of the zebrafish voltage-dependent anion channel 2 reveal an oligomeric population.
abstract: In recent years, there has been a vast increase in structural and functional understanding of VDAC1, but VDAC2 and -3 have been understudied despite having many unique phenotypes. One reason for the paucity of structural and biochemical characterization of the VDAC2 and -3 isoforms stems from the inability of obtaining purified, functional protein. Here we demonstrate the expression, isolation, and basic characterization of zebrafish VDAC2 (zfVDAC2). Further, we resolved the structure of zfVDAC2 at 2.8 Å resolution, revealing a crystallographic dimer. The dimer orientation was confirmed in solution by double electron-electron resonance spectroscopy and by cross-linking experiments disclosing a dimer population of ∼20% in lauryldimethine amine oxide detergent micelles, whereas in lipidic bicelles a higher population of dimeric and higher order oligomers species were observed. The present study allows for a more accurate structural comparison between VDAC2 and its better-studied counterpart VDAC1.
authors.affiliation: From the Department of Molecular, Cell and Developmental Biology.
authors.forename: Johann
authors.initials: J
authors.lastname: Schredelseker
authors.forename: Aviv
authors.initials: A
authors.lastname: Paz
authors.forename: Carlos J
authors.initials: CJ
authors.lastname: López
authors.forename: Christian
authors.initials: C
authors.lastname: Altenbach
authors.forename: Calvin S
authors.initials: CS
authors.lastname: Leung
authors.forename: Maria K
authors.initials: MK
authors.lastname: Drexler
authors.forename: Jau-Nian
authors.initials: JN
authors.lastname: Chen
authors.forename: Wayne L
authors.initials: WL
authors.lastname: Hubbell
authors.forename: Jeff
authors.initials: J
authors.lastname: Abramson
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D018360:Crystallography, X-Ray; D003545:Cysteine / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D004553:Electric Conductivity; D004578:Electron Spin Resonance Spectroscopy / Q000379:methods*; D004591:Electrophoresis, Polyacrylamide Gel; D008051:Lipid Bilayers / Q000737:chemistry; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009154:Mutation; D011487:Protein Conformation; D055503:Protein Multimerization; D017433:Protein Structure, Secondary; D017386:Sequence Homology, Amino Acid; D055672:Static Electricity; D050996:Voltage-Dependent Anion Channel 2 / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D029961:Zebrafish Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism
chemical_list: D008051:Lipid Bilayers; D050996:Voltage-Dependent Anion Channel 2; D029961:Zebrafish Proteins; D003545:Cysteine
keywords: Biophysics; DEER; Ion Channels; Mitochondria; VDAC2; X-ray Crystallography; Zebrafish