View source for 2g4e


==Crystal structure of transthyretin mutant I84A at neutral pH==
<StructureSection load='2g4e' size='340' side='right'caption='[[2g4e]], [[Resolution|resolution]] 2.17&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[2g4e]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2G4E OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2G4E FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2.17&#8491;</td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=2g4e FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2g4e OCA], [https://pdbe.org/2g4e PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2g4e RCSB], [https://www.ebi.ac.uk/pdbsum/2g4e PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2g4e ProSAT]</span></td></tr>
</table>
== Disease ==
[https://www.uniprot.org/uniprot/TTHY_HUMAN TTHY_HUMAN] Defects in TTR are the cause of amyloidosis transthyretin-related (AMYL-TTR) [MIM:[https://omim.org/entry/105210 105210]. A hereditary generalized amyloidosis due to transthyretin amyloid deposition. Protein fibrils can form in different tissues leading to amyloid polyneuropathies, amyloidotic cardiomyopathy, carpal tunnel syndrome, systemic senile amyloidosis. The disease includes leptomeningeal amyloidosis that is characterized by primary involvement of the central nervous system. Neuropathologic examination shows amyloid in the walls of leptomeningeal vessels, in pia arachnoid, and subpial deposits. Some patients also develop vitreous amyloid deposition that leads to visual impairment (oculoleptomeningeal amyloidosis). Clinical features include seizures, stroke-like episodes, dementia, psychomotor deterioration, variable amyloid deposition in the vitreous humor.<ref>PMID:11243784</ref> <ref>PMID:15735344</ref> <ref>PMID:19167329</ref> <ref>PMID:3818577</ref> <ref>PMID:3022108</ref> <ref>PMID:6651852</ref> <ref>PMID:6583672</ref> <ref>PMID:3135807</ref> <ref>PMID:1517749</ref> <ref>PMID:1932142</ref> <ref>PMID:7923855</ref> <ref>PMID:8382610</ref> <ref>PMID:8428915</ref> <ref>PMID:9733771</ref> <ref>PMID:12403615</ref> <ref>PMID:16185074</ref> <ref>PMID:16627944</ref> <ref>PMID:6487335</ref> <ref>PMID:3722385</ref> <ref>PMID:2891727</ref> <ref>PMID:2161654</ref> <ref>PMID:2363717</ref> <ref>PMID:1656975</ref> <ref>PMID:2046936</ref> <ref>PMID:1570831</ref> <ref>PMID:1734866</ref> <ref>PMID:1520326</ref> <ref>PMID:1520336</ref> <ref>PMID:1544214</ref> <ref>PMID:1351039</ref> <ref>PMID:1301926</ref> <ref>PMID:1362222</ref> <ref>PMID:1436517</ref> <ref>PMID:8352764</ref> <ref>PMID:8038017</ref> <ref>PMID:8257997</ref> <ref>PMID:8095302</ref> <ref>PMID:1997217</ref> <ref>PMID:8019560</ref> <ref>PMID:8081397</ref> <ref>PMID:7914929</ref> <ref>PMID:8133316</ref> <ref>PMID:7910950</ref> <ref>PMID:7655883</ref> <ref>PMID:7850982</ref> <ref>PMID:8579098</ref> <ref>PMID:9066351</ref> <ref>PMID:8990019</ref> <ref>PMID:9605286</ref> <ref>PMID:10036587</ref> <ref>PMID:10627135</ref> <ref>PMID:10694917</ref> <ref>PMID:10211412</ref> <ref>PMID:10439117</ref> <ref>PMID:10611950</ref> <ref>PMID:10071047</ref> <ref>PMID:10436378</ref> <ref>PMID:10842705</ref> <ref>PMID:10842718</ref> <ref>PMID:10882995</ref> <ref>PMID:11445644</ref> <ref>PMID:12557757</ref> <ref>PMID:11866053</ref> <ref>PMID:12050338</ref> <ref>PMID:12771253</ref> <ref>PMID:15214015</ref> <ref>PMID:15478468</ref> <ref>PMID:15217993</ref> <ref>PMID:17453626</ref> <ref>PMID:17577687</ref> <ref>PMID:17503405</ref> <ref>PMID:17635579</ref>   Defects in TTR are a cause of hyperthyroxinemia dystransthyretinemic euthyroidal (HTDE) [MIM:[https://omim.org/entry/145680 145680]. It is a condition characterized by elevation of total and free thyroxine in healthy, euthyroid persons without detectable binding protein abnormalities.<ref>PMID:1979335</ref>   Defects in TTR are a cause of carpal tunnel syndrome type 1 (CTS1) [MIM:[https://omim.org/entry/115430 115430]. It is a condition characterized by entrapment of the median nerve within the carpal tunnel. Symptoms include burning pain and paresthesias involving the ventral surface of the hand and fingers which may radiate proximally. Impairment of sensation in the distribution of the median nerve and thenar muscle atrophy may occur. This condition may be associated with repetitive occupational trauma, wrist injuries, amyloid neuropathies, rheumatoid arthritis.<ref>PMID:8309582</ref> 
== Function ==
[https://www.uniprot.org/uniprot/TTHY_HUMAN TTHY_HUMAN] Thyroid hormone-binding protein. Probably transports thyroxine from the bloodstream to the brain.<ref>PMID:3714052</ref> 
== Evolutionary Conservation ==
[[Image:Consurf_key_small.gif|200px|right]]
Check<jmol>
  <jmolCheckbox>
    <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/g4/2g4e_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked>
    <text>to colour the structure by Evolutionary Conservation</text>
  </jmolCheckbox>
</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=2g4e ConSurf].
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== Publication Abstract from PubMed ==
Several proteins, including transthyretin (TTR), can generate in tissues extracellular insoluble aggregates, in the form of fibrils, that are associated with pathological states known as amyloidoses. To date, more than 80 different TTR point mutations have been associated with hereditary amyloidosis in humans. In vitro, the formation of amyloid fibrils by human TTR is known to be triggered by acidic pH. We show here that, in vitro, the natural amyloidogenic I84S and the non-natural I84A TTR mutant forms exhibit a propensity to produce fibrils in an acidic medium significantly higher than that of wild-type TTR. The two mutant forms have been crystallized at both neutral and acidic pH. Their neutral pH crystal structures are very similar to that of wild-type TTR, consistent with previous evidence indicating that only minor structural changes are induced by amyloidogenic mutations. On the contrary, their crystal structures at moderately low pH (4.6) show significant conformational differences as compared to their neutral pH structures. Remarkably, such changes are not induced in wild-type TTR crystallized at low pH. The most relevant consist of the unwinding of the TTR short alpha-helix and of the change in conformation of the loop connecting the alpha-helix to beta-strand F. Only one monomer of the crystallographic dimer is affected, causing a disruption of the tetrameric symmetry. This asymmetry and a possible destabilization of the tetrameric quaternary structure of TTR may be responsible for the amyloidogenic potential of the two TTR mutant forms at low pH.

Acidic pH-induced conformational changes in amyloidogenic mutant transthyretin.,Pasquato N, Berni R, Folli C, Alfieri B, Cendron L, Zanotti G J Mol Biol. 2007 Feb 23;366(3):711-9. Epub 2006 Dec 1. PMID:17196219<ref>PMID:17196219</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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<div class="pdbe-citations 2g4e" style="background-color:#fffaf0;"></div>

==See Also==
*[[Transthyretin 3D structures|Transthyretin 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Berni R]]
[[Category: Folli C]]
[[Category: Pasquato N]]
[[Category: Zanotti G]]