View source for 2bbc


==Structure of Cobalamin-complexed Bovine Transcobalamin in trigonal crystal form==
<StructureSection load='2bbc' size='340' side='right'caption='[[2bbc]], [[Resolution|resolution]] 2.40&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[2bbc]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Bos_taurus Bos taurus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2BBC OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2BBC 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]] 2.4&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CL:CHLORIDE+ION'>CL</scene></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=2bbc FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2bbc OCA], [https://pdbe.org/2bbc PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2bbc RCSB], [https://www.ebi.ac.uk/pdbsum/2bbc PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2bbc ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/TCO2_BOVIN TCO2_BOVIN] Primary vitamin B12-binding and transport protein. Delivers cobalamin to cells.
== 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/bb/2bbc_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview03.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=2bbc ConSurf].
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== Publication Abstract from PubMed ==
Cobalamin (Cbl, vitamin B(12)) serves for two essential cofactors in mammals. The pathway for its intestinal absorption, plasma transport, and cellular uptake uses cell surface receptors and three Cbl-transporting proteins, haptocorrin, intrinsic factor, and transcobalamin (TC). We present the structure determination of a member of the mammalian Cbl-transporter family. The crystal structures of recombinant human and bovine holo-TCs reveal a two-domain architecture, with an N-terminal alpha(6)-alpha(6) barrel and a smaller C-terminal domain. One Cbl molecule in base-on conformation is buried inside the domain interface. Structural data combined with previous binding assays indicate a domain motion in the first step of Cbl binding. In a second step, the weakly coordinated ligand H(2)O at the upper axial side of added H(2)O-Cbl is displaced by a histidine residue of the alpha(6)-alpha(6) barrel. Analysis of amino acid conservation on TC's surface in orthologous proteins suggests the location of the TC-receptor-recognition site in an extended region on the alpha(6)-alpha(6) barrel. The TC structure allows for the mapping of sites of amino acid variation due to polymorphisms of the human TC gene. Structural information is used to predict the overall fold of haptocorrin and intrinsic factor and permits a rational approach to the design of new Cbl-based bioconjugates for diagnostic or therapeutic drug delivery.

Structural basis for mammalian vitamin B12 transport by transcobalamin.,Wuerges J, Garau G, Geremia S, Fedosov SN, Petersen TE, Randaccio L Proc Natl Acad Sci U S A. 2006 Mar 21;103(12):4386-91. Epub 2006 Mar 14. PMID:16537422<ref>PMID:16537422</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Bos taurus]]
[[Category: Large Structures]]
[[Category: Fedosov SN]]
[[Category: Garau G]]
[[Category: Geremia S]]
[[Category: Petersen TE]]
[[Category: Randaccio L]]
[[Category: Wuerges J]]