View source for 1hqk


==CRYSTAL STRUCTURE ANALYSIS OF LUMAZINE SYNTHASE FROM AQUIFEX AEOLICUS==
<StructureSection load='1hqk' size='340' side='right'caption='[[1hqk]], [[Resolution|resolution]] 1.60&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1hqk]] is a 5 chain structure with sequence from [https://en.wikipedia.org/wiki/"aquifex_aeolicus"_huber_and_stetter_2001 "aquifex aeolicus" huber and stetter 2001]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1HQK OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1HQK FirstGlance]. <br>
</td></tr><tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[https://en.wikipedia.org/wiki/6,7-dimethyl-8-ribityllumazine_synthase 6,7-dimethyl-8-ribityllumazine synthase], with EC number [https://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.5.1.78 2.5.1.78] </span></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=1hqk FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1hqk OCA], [https://pdbe.org/1hqk PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1hqk RCSB], [https://www.ebi.ac.uk/pdbsum/1hqk PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1hqk ProSAT]</span></td></tr>
</table>
== Function ==
[[https://www.uniprot.org/uniprot/RISB_AQUAE RISB_AQUAE]] Catalyzes the formation of 6,7-dimethyl-8-ribityllumazine by condensation of 5-amino-6-(D-ribitylamino)uracil with 3,4-dihydroxy-2-butanone 4-phosphate. This is the penultimate step in the biosynthesis of riboflavin.<ref>PMID:12603336</ref> <ref>PMID:11237620</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/hq/1hqk_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=1hqk ConSurf].
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== Publication Abstract from PubMed ==
An open reading frame optimized for expression of 6,7-dimethyl-8-ribityl-lumazine synthase of the hyperthermophilic bacterium Aquifex aeolicus in Escherichia coli was synthesized and expressed in a recombinant E. coli strain to a level of around 15 %. The recombinant protein was purified by heat-treatment and gel-filtration. The protein was crystallized in the cubic space group I23 with the cell dimensions a = b = c = 180.8 A, and diffraction data were collected to 1.6 A resolution. The structure was solved by molecular replacement using lumazine synthase from Bacillus subtilis as search model. The structure of the A. aeolicus enzyme was refined to a resolution of 1.6 A. The spherical protein consists of 60 identical subunits with strict icosahedral 532 symmetry. The subunit fold is closely related to that of the B. subtilis enzyme (rmsd 0.80 A). The extremely thermostable lumazine synthase from A. aeolicus has a melting temperature of 119.9 degrees C. Compared to other icosahedral and pentameric lumazine synthases, the A. aeolicus enzyme has the largest accessible surface presented by charged residues and the smallest surface presented by hydrophobic residues. It also has the largest number of ion-pairs per subunit. Two ion-pair networks involving two, respectively three, stacking arginine residues assume a distinct role in linking adjacent subunits. The findings indicate the influence of the optimization of hydrophobic and ionic contacts in gaining thermostability.

X-ray structure analysis and crystallographic refinement of lumazine synthase from the hyperthermophile Aquifex aeolicus at 1.6 A resolution: determinants of thermostability revealed from structural comparisons.,Zhang X, Meining W, Fischer M, Bacher A, Ladenstein R J Mol Biol. 2001 Mar 9;306(5):1099-114. PMID:11237620<ref>PMID:11237620</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 1hqk" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Aquifex aeolicus huber and stetter 2001]]
[[Category: 6,7-dimethyl-8-ribityllumazine synthase]]
[[Category: Large Structures]]
[[Category: Bacher, A]]
[[Category: Fischer, M]]
[[Category: Ladenstein, R]]
[[Category: Meining, W]]
[[Category: Zhang, X]]
[[Category: Aquifex aeolicus]]
[[Category: Enzyme stability]]
[[Category: Lumazine synthase]]
[[Category: Transferase]]
[[Category: Vitamin biosynthesis]]
[[Category: X-ray structure analysis]]