1oip

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The Molecular Basis of Vitamin E Retention: Structure of Human Alpha-Tocopherol Transfer ProteinThe Molecular Basis of Vitamin E Retention: Structure of Human Alpha-Tocopherol Transfer Protein

Structural highlights

1oip is a 1 chain structure with sequence from Homo sapiens. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:X-ray diffraction, Resolution 1.95Å
Ligands:,
Resources:FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Disease

TTPA_HUMAN Defects in TTPA are the cause of ataxia with isolated vitamin E deficiency (AVED) [MIM:277460. AVED is an autosomal recessive disease characterized by spinocerebellar degeneration. It causes ataxia and peripheral neuropathy that resembles Friedreich ataxia. AVED patients have markedly reduced plasma levels of vitamin E.[1] [2] [3] [4] [5] [6]

Function

TTPA_HUMAN Binds alpha-tocopherol and enhances its transfer between separate membranes.

Evolutionary Conservation

Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.

Publication Abstract from PubMed

Alpha-tocopherol transfer protein (alpha-TTP) is a liver protein responsible for the selective retention of alpha-tocopherol from dietary vitamin E, which is a mixture of alpha, beta, gamma, and delta-tocopherols and the corresponding tocotrienols. The alpha-TTP-mediated transfer of alpha-tocopherol into nascent VLDL is the major determinant of plasma alpha-tocopherol levels in humans. Mutations in the alpha-TTP gene have been detected in patients suffering from low plasma alpha-tocopherol and ataxia with isolated vitamin E deficiency (AVED). The crystal structure of alpha-TTP reveals two conformations. In its closed tocopherol-charged form, a mobile helical surface segment seals the hydrophobic binding pocket. In the presence of detergents, an open conformation is observed, which probably represents the membrane-bound form. The selectivity of alpha-TTP for RRR-alpha-tocopherol is explained from the van der Waals contacts occurring in the lipid-binding pocket. Mapping the known mutations leading to AVED onto the crystal structure shows that no mutations occur directly in the binding pocket.

The molecular basis of vitamin E retention: structure of human alpha-tocopherol transfer protein.,Meier R, Tomizaki T, Schulze-Briese C, Baumann U, Stocker A J Mol Biol. 2003 Aug 15;331(3):725-34. PMID:12899840[7]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

References

  1. ↑ Hentati A, Deng HX, Hung WY, Nayer M, Ahmed MS, He X, Tim R, Stumpf DA, Siddique T, Ahmed. Human alpha-tocopherol transfer protein: gene structure and mutations in familial vitamin E deficiency. Ann Neurol. 1996 Mar;39(3):295-300. PMID:8602747 doi:http://dx.doi.org/10.1002/ana.410390305
  2. ↑ Cavalier L, Ouahchi K, Kayden HJ, Di Donato S, Reutenauer L, Mandel JL, Koenig M. Ataxia with isolated vitamin E deficiency: heterogeneity of mutations and phenotypic variability in a large number of families. Am J Hum Genet. 1998 Feb;62(2):301-10. PMID:9463307 doi:S0002-9297(07)63495-8
  3. ↑ Ouahchi K, Arita M, Kayden H, Hentati F, Ben Hamida M, Sokol R, Arai H, Inoue K, Mandel JL, Koenig M. Ataxia with isolated vitamin E deficiency is caused by mutations in the alpha-tocopherol transfer protein. Nat Genet. 1995 Feb;9(2):141-5. PMID:7719340 doi:http://dx.doi.org/10.1038/ng0295-141
  4. ↑ Gotoda T, Arita M, Arai H, Inoue K, Yokota T, Fukuo Y, Yazaki Y, Yamada N. Adult-onset spinocerebellar dysfunction caused by a mutation in the gene for the alpha-tocopherol-transfer protein. N Engl J Med. 1995 Nov 16;333(20):1313-8. PMID:7566022
  5. ↑ Morley S, Panagabko C, Shineman D, Mani B, Stocker A, Atkinson J, Manor D. Molecular determinants of heritable vitamin E deficiency. Biochemistry. 2004 Apr 13;43(14):4143-9. PMID:15065857 doi:10.1021/bi0363073
  6. ↑ Mariotti C, Gellera C, Rimoldi M, Mineri R, Uziel G, Zorzi G, Pareyson D, Piccolo G, Gambi D, Piacentini S, Squitieri F, Capra R, Castellotti B, Di Donato S. Ataxia with isolated vitamin E deficiency: neurological phenotype, clinical follow-up and novel mutations in TTPA gene in Italian families. Neurol Sci. 2004 Jul;25(3):130-7. PMID:15300460 doi:10.1007/s10072-004-0246-z
  7. ↑ Meier R, Tomizaki T, Schulze-Briese C, Baumann U, Stocker A. The molecular basis of vitamin E retention: structure of human alpha-tocopherol transfer protein. J Mol Biol. 2003 Aug 15;331(3):725-34. PMID:12899840

1oip, resolution 1.95Å

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