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TOM Complex
The translocase of the outer membrane (TOM) is a complex of proteins found in the outer mitochondrial membrane of the mitochondria. It allows movement of proteins through this barrier and into the intermembrane space of the mitochondrion. Most of the proteins needed for mitochondrial function are encoded by the nucleus of the cell. The outer membrane of the mitochondrion is impermeable to large molecules greater than 5000 Daltons. The TOM works in conjunction with the translocase of the inner membrane (TIM) to translocate proteins into the mitochondrion. Many of the proteins in the TOM complex, such as TOMM22, were first identified in ''Neurospora crassa'' and ''Saccharomyces cerevisiae''. Many of the genes encoding these proteins are designated as TOMM (translocase of the outer mitochondrial membrane) complex genes. The complete mitochondrial protein translocase complex includes at least 19 proteins: several chaperones, four proteins of the outer membrane translocase (Tom) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Outer Mitochondrial Membrane
A mitochondrion (; ) is an organelle found in the cells of most Eukaryotes, such as animals, plants and fungi. Mitochondria have a double membrane structure and use aerobic respiration to generate adenosine triphosphate (ATP), which is used throughout the cell as a source of chemical energy. They were discovered by Albert von Kölliker in 1857 in the voluntary muscles of insects. The term ''mitochondrion'' was coined by Carl Benda in 1898. The mitochondrion is popularly nicknamed the "powerhouse of the cell", a phrase coined by Philip Siekevitz in a 1957 article of the same name. Some cells in some multicellular organisms lack mitochondria (for example, mature mammalian red blood cells). A large number of unicellular organisms, such as microsporidia, parabasalids and diplomonads, have reduced or transformed their mitochondria into other structures. One eukaryote, ''Monocercomonoides'', is known to have completely lost its mitochondria, and one multicellular organism, '' Henn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inner Mitochondrial Membrane
The inner mitochondrial membrane (IMM) is the mitochondrial membrane which separates the mitochondrial matrix from the intermembrane space. Structure The structure of the inner mitochondrial membrane is extensively folded and compartmentalized. The numerous invaginations of the membrane are called cristae, separated by crista junctions from the inner boundary membrane juxtaposed to the outer membrane. Cristae significantly increase the total membrane surface area compared to a smooth inner membrane and thereby the available working space for oxidative phosphorylation. The inner membrane creates two compartments. The region between the inner and outer membrane, called the intermembrane space, is largely continuous with the cytosol, while the more sequestered space inside the inner membrane is called the matrix. Cristae For typical liver mitochondria, the area of the inner membrane is about 5 times as large as the outer membrane due to cristae. This ratio is variable and mitocho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transport Proteins
A transport protein (variously referred to as a transmembrane pump, transporter, escort protein, acid transport protein, cation transport protein, or anion transport protein) is a protein that serves the function of moving other materials within an organism. Transport proteins are vital to the growth and life of all living things. There are several different kinds of transport proteins. Carrier proteins are proteins involved in the movement of ions, small molecules, or macromolecules, such as another protein, across a biological membrane. Carrier proteins are integral membrane proteins; that is, they exist within and span the membrane across which they transport substances. The proteins may assist in the movement of substances by facilitated diffusion (i.e., passive transport) or active transport. These mechanisms of movement are known as carrier-mediated transport. Each carrier protein is designed to recognize only one substance or one group of very similar substances. Research ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sorting And Assembly Machinery
The outer mitochondrial membrane is made up of two essential proteins, Tom40 and Sam50. Tom40 Tom40 is a protein import pore required for the import of precursor proteins across the outer mitochondrial membrane, and it makes up part of the translocase of the outer membrane. Sam50 Sam50 is a subunit of the sorting and assembly machinery (SAM) of the outer membrane. The sorting and assembly machinery is a protein complex, that operates after the translocase of the outer membrane, to mediate insertion of beta barrel proteins into the outer mitochondrial membrane. Complex components The sorting and assembly machinery is made up of three subunits, Sam35, Sam37, and Sam50, of which Sam50 is embedded within the outer mitochondrial membrane.Bolender, N., Sickmann, A., Wagner, R., Meisinger, C., Pfanner, N. (2008) Multiple pathways for sorting mitochondrial precursor proteins. EMBO J 9(1): 42-49. Both Sam35 and Sam37 are located on the cytosolic face of the SAM complex are periphera ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TOMM70A
Mitochondrial import receptor subunit TOM70 is a protein that in humans is encoded by the ''TOMM70A'' gene. The translocase of outer mitochondrial membrane (TOM) complex is a multisubunit complex involved in the recognition, unfolding, and translocation of preproteins into the mitochondria. See TIM17A (MIM 605057). upplied by OMIMref name="entrez" /> See also * Mitochondria Outer Membrane Translocase * TOMM20 * TOMM22 * TOMM40 Translocase of outer mitochondrial membrane 40 homolog (yeast), also known as TOMM40, is a protein which in humans is encoded by the ''TOMM40'' gene. Function ''TOMM40'' codes for a protein that is embedded into outer membranes of mitochondria ... References Further reading * * * * * * * * * {{gene-3-stub Co-chaperones ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Translocase Of The Inner Membrane
The translocase of the inner membrane (TIM) is a complex of proteins found in the inner mitochondrial membrane of the mitochondria. Components of the TIM complex facilitate the translocation of proteins across the inner membrane and into the mitochondrial matrix. They also facilitate the insertion of proteins into the inner mitochondrial membrane, where they must reside in order to function, these mainly include members of the mitochondrial carrier family of proteins. The TIM23 complex The TIM23 complex facilitates translocation of matrix-targeted proteins into the mitochondrial matrix. These proteins contain a cleavable presequence. The TIM23 complex is made up of the subunits Tim17, Tim21 and Tim23, which are thought to contribute to the structural formation of the translocation channel that spans the inner membrane, and Tim44, which is a peripheral membrane protein. Tim44 is only weakly associated with Tim23 and is located on the matrix side of the inner membrane. At the openin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TOMM40
Translocase of outer mitochondrial membrane 40 homolog (yeast), also known as TOMM40, is a protein which in humans is encoded by the ''TOMM40'' gene. Function ''TOMM40'' codes for a protein that is embedded into outer membranes of mitochondria and is required for the movement of proteins into mitochondria. More precisely, TOMM40 is the channel-forming subunit of a translocase of the mitochondrial outer membrane ( TOM) that is essential for protein transport into mitochondria. Clinical significance In humans, certain alleles of this gene have been statistically associated with an increased risk of developing late-onset Alzheimer's disease.; One study has found that TOMM40 risk alleles appears twice as often in people with Alzheimer's disease than those without it. Because ''TOMM40'' is located on chromosome 19, and is closely adjacent to ''APOE'', another gene known to be associated with Alzheimer's, another study has suggested that the statistically significant correlatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atomic Mass Unit
The dalton or unified atomic mass unit (symbols: Da or u) is a non-SI unit of mass widely used in physics and chemistry. It is defined as of the mass of an unbound neutral atom of carbon-12 in its nuclear and electronic ground state and at rest. The atomic mass constant, denoted ''m''u, is defined identically, giving . This unit is commonly used in physics and chemistry to express the mass of atomic-scale objects, such as atoms, molecules, and elementary particles, both for discrete instances and multiple types of ensemble averages. For example, an atom of helium-4 has a mass of . This is an intrinsic property of the isotope and all helium-4 atoms have the same mass. Acetylsalicylic acid (aspirin), , has an average mass of approximately . However, there are no acetylsalicylic acid molecules with this mass. The two most common masses of individual acetylsalicylic acid molecules are , having the most common isotopes, and , in which one carbon is carbon-13. The molecular mass ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TOMM20
Mitochondrial import receptor subunit TOM20 homolog is a protein that in humans is encoded by the ''TOMM20'' gene. TOM20 is one of the receptor systems of the TOM complex (translocase of the outer membrane) in the outer mitochondrial membrane (OMM). Function In mitochondrial protein import, TOM20 is closely associated with the pore-forming TOM40 complex and acts by recognizing and binding the N-terminal MTSs (matrix-targeting sequences), which form an amphipathic alpha helix and aid passage of the target proteins into the mitochondrial matrix. See also * Mitochondria Outer Membrane Translocase * TOMM22 * TOMM40 * TOMM70A Mitochondrial import receptor subunit TOM70 is a protein that in humans is encoded by the ''TOMM70A'' gene In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meani ... References Further reading * * * * * * * * * * * * * * * {{gene-1-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
