title: The alpha and the beta: protein translocation across mitochondrial and plastid outer membranes.
abstract: In the evolution of mitochondria and plastids from endosymbiotic bacteria, most of the proteins that make up these organelles have become encoded by nuclear genes and must therefore be transported across the organellar membranes, following synthesis in the cytosol. The core component of the protein translocation machines in both the mitochondrial and plastid outer membranes appears to be a beta-barrel protein, perhaps a relic from their bacterial ancestry, distinguishing these translocases from the alpha-helical-based protein translocation pores found in all other eukaryotic membranes.
authors.affiliation: Russell Grimwade School of Biochemistry and Molecular Biology, University of Melbourne, Parkville, 3010, Australia.
authors.forename: K
authors.initials: K
authors.lastname: Gabriel
authors.forename: S K
authors.initials: SK
authors.lastname: Buchanan
authors.forename: T
authors.initials: T
authors.lastname: Lithgow
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism; D029968:Escherichia coli Proteins; D007425:Intracellular Membranes / Q000378:metabolism; D008565:Membrane Proteins / Q000737:chemistry* / Q000378:metabolism*; D026901:Membrane Transport Proteins; D008928:Mitochondria / Q000378:metabolism*; D033681:Mitochondrial Membrane Transport Proteins; D010940:Plant Proteins; D018087:Plastids / Q000378:metabolism*; D018272:Porins / Q000378:metabolism; D011487:Protein Conformation; D011498:Protein Precursors / Q000378:metabolism; D021381:Protein Transport; D000069816:SEC Translocation Channels; D029701:Saccharomyces cerevisiae Proteins; D050994:Voltage-Dependent Anion Channels
chemical_list: D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D008565:Membrane Proteins; D026901:Membrane Transport Proteins; D033681:Mitochondrial Membrane Transport Proteins; C103933:OEP75 protein precursor, plant; D010940:Plant Proteins; D018272:Porins; D011498:Protein Precursors; D000069816:SEC Translocation Channels; D029701:Saccharomyces cerevisiae Proteins; C057841:SecY protein, E coli; C066555:Tom40 protein, S cerevisiae; D050994:Voltage-Dependent Anion Channels