View source for 1f7b


==CRYSTAL STRUCTURE ANALYSIS OF N-ACETYLNEURAMINATE LYASE FROM HAEMOPHILUS INFLUENZAE: CRYSTAL FORM II IN COMPLEX WITH 4-OXO-SIALIC ACID==
<StructureSection load='1f7b' size='340' side='right'caption='[[1f7b]], [[Resolution|resolution]] 1.80&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1f7b]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Haemophilus_influenzae Haemophilus influenzae]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1F7B OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1F7B 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]] 1.8&#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>, <scene name='pdbligand=NAU:4,4,6,7,8,9-HEXAHYDROXY-5-METHYLCARBOXAMIDONONANOIC+ACID'>NAU</scene>, <scene name='pdbligand=NAV:6,7,8,9-TETRAHYDROXY-5-METHYLCARBOXAMIDO-4-OXONONANOIC+ACID'>NAV</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=1f7b FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1f7b OCA], [https://pdbe.org/1f7b PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1f7b RCSB], [https://www.ebi.ac.uk/pdbsum/1f7b PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1f7b ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/NANA_HAEIN NANA_HAEIN] Catalyzes the cleavage of N-acetylneuraminic acid (sialic acid) to form pyruvate and N-acetylmannosamine via a Schiff base intermediate.
== 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/f7/1f7b_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=1f7b ConSurf].
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== Publication Abstract from PubMed ==
The N-acetylneuraminate lyase (NAL) sub-family of (beta/alpha)(8) enzymes share a common catalytic step but catalyse reactions in different biological pathways. Known examples include NAL, dihydrodipicolinate synthetase (DHDPS), d-5-keto-4-deoxyglucarate dehydratase, 2-keto-3-deoxygluconate aldolase, trans-o-hydroxybenzylidenepyruvate hydrolase-aldolase and trans-2'-carboxybenzalpyruvate hydratase-aldolase. Little is known about the way in which the three-dimensional structure of the respective active sites are modulated across the sub-family to achieve cognate substrate recognition. We present here the structure of Haemophilus influenzae NAL determined by X-ray crystallography to a maximum resolution of 1.60 A, in native form and in complex with three substrate analogues (sialic acid alditol, 4-deoxy-sialic acid and 4-oxo-sialic acid). These structures reveal for the first time the mode of binding of the complete substrate in the NAL active site. On the basis of the above structures, that of substrate-complexed DHDPS and sequence comparison across the sub-family we are able to propose a unified model for active site modulation. The model is one of economy, allowing wherever appropriate the retention or relocation of residues associated with binding common substrate substituent groups. Our structures also suggest a role for the strictly conserved tyrosine residue found in all active sites of the sub-family, namely that it mediates proton abstraction by the alpha-keto acid carboxylate in a substrate-assisted catalytic reaction pathway.

Active site modulation in the N-acetylneuraminate lyase sub-family as revealed by the structure of the inhibitor-complexed Haemophilus influenzae enzyme.,Barbosa JA, Smith BJ, DeGori R, Ooi HC, Marcuccio SM, Campi EM, Jackson WR, Brossmer R, Sommer M, Lawrence MC J Mol Biol. 2000 Oct 27;303(3):405-21. PMID:11031117<ref>PMID:11031117</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 1f7b" style="background-color:#fffaf0;"></div>

==See Also==
*[[N-acetylneuraminate lyase 3D structures|N-acetylneuraminate lyase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Haemophilus influenzae]]
[[Category: Large Structures]]
[[Category: Barbosa JARG]]
[[Category: DeGori R]]
[[Category: Lawrence MC]]
[[Category: Smith BJ]]