Structural analysis of mitochondrial pores.
Structural information about the channel in the mitochondrial outer membrane, derived from sequence analysis and electron microscopy of two-dimensional crystals, is summarized. A model for the channel is presented, consisting of a cylindrical beta-barrel that is formed by one or two 30-kDa polypeptides, with an alpha-carbon backbone diameter of 3.8 nm. The radial distributions of basic amino acids and lipid-contact regions on the projected cylinder are mapped relative to interchannel bonding sites inferred from channel packing in the arrays. Speculation on the kinds of conformational changes that the channel might undergo is also presented.
Mannella
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Wadsworth Center for Laboratories and Research, New York State Department of Health, Albany 12201-0509.
D000595:Amino Acid Sequence; D007425:Intracellular Membranes; D007473:Ion Channels; D008565:Membrane Proteins; D008854:Microscopy, Electron; D008928:Mitochondria / Q000648:ultrastructure*; D008969:Molecular Sequence Data; D010944:Plants; D018272:Porins; D050994:Voltage-Dependent Anion Channels
D007473:Ion Channels; D008565:Membrane Proteins; D018272:Porins; D050994:Voltage-Dependent Anion Channels