View source for 1hxd


==CRYSTAL STRUCTURE OF E. COLI BIOTIN REPRESSOR WITH BOUND BIOTIN==
<StructureSection load='1hxd' size='340' side='right'caption='[[1hxd]], [[Resolution|resolution]] 2.40&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1hxd]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1HXD OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1HXD 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=BTN:BIOTIN'>BTN</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=1hxd FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1hxd OCA], [https://pdbe.org/1hxd PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1hxd RCSB], [https://www.ebi.ac.uk/pdbsum/1hxd PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1hxd ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/BIRA_ECOLI BIRA_ECOLI] Acts both as a biotin--[acetyl-CoA-carboxylase] ligase and a biotin-operon repressor. In the presence of ATP, BirA activates biotin to form the BirA-biotinyl-5'-adenylate (BirA-bio-5'-AMP or holoBirA) complex. HoloBirA can either transfer the biotinyl moiety to the biotin carboxyl carrier protein (BCCP) subunit of acetyl-CoA carboxylase, or bind to the biotin operator site and inhibit transcription of the operon.<ref>PMID:6129246</ref> <ref>PMID:2667763</ref> <ref>PMID:8003500</ref> <ref>PMID:12527300</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/hx/1hxd_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=1hxd ConSurf].
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== Publication Abstract from PubMed ==
The Escherichia coli biotin repressor binds to the biotin operator to repress transcription of the biotin biosynthetic operon. In this work, a structure determined by x-ray crystallography of a complex of the repressor bound to biotin, which also functions as an activator of DNA binding by the biotin repressor (BirA), is described. In contrast to the monomeric aporepressor, the complex is dimeric with an interface composed in part of an extended beta-sheet. Model building, coupled with biochemical data, suggests that this is the dimeric form of BirA that binds DNA. Segments of three surface loops that are disordered in the aporepressor structure are located in the interface region of the dimer and exhibit greater order than was observed in the aporepressor structure. The results suggest that the corepressor of BirA causes a disorder-to-order transition that is a prerequisite to repressor dimerization and DNA binding.

Corepressor-induced organization and assembly of the biotin repressor: a model for allosteric activation of a transcriptional regulator.,Weaver LH, Kwon K, Beckett D, Matthews BW Proc Natl Acad Sci U S A. 2001 May 22;98(11):6045-50. Epub 2001 May 15. PMID:11353844<ref>PMID:11353844</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 1hxd" style="background-color:#fffaf0;"></div>

==See Also==
*[[Biotin Protein Ligase 3D structures|Biotin Protein Ligase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Escherichia coli]]
[[Category: Large Structures]]
[[Category: Beckett D]]
[[Category: Kwon K]]
[[Category: Ruparelia S]]
[[Category: Streaker ED]]