View source for 1a04


==THE STRUCTURE OF THE NITRATE/NITRITE RESPONSE REGULATOR PROTEIN NARL IN THE MONOCLINIC C2 CRYSTAL FORM==
<StructureSection load='1a04' size='340' side='right'caption='[[1a04]], [[Resolution|resolution]] 2.20&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1a04]] 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=1A04 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1A04 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]] 2.2&#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=1a04 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1a04 OCA], [https://pdbe.org/1a04 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1a04 RCSB], [https://www.ebi.ac.uk/pdbsum/1a04 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1a04 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/NARL_ECOLI NARL_ECOLI] This protein activates the expression of the nitrate reductase (narGHJI) and formate dehydrogenase-N (fdnGHI) operons and represses the transcription of the fumarate reductase (frdABCD) operon in response to a nitrate/nitrite induction signal transmitted by either the NarX or NarQ proteins.
== 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/a0/1a04_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=1a04 ConSurf].
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== Publication Abstract from PubMed ==
The structure of the Escherichia coli response regulator NarL has been solved in a new, monoclinic space group, and compared with the earlier orthorhombic crystal structure. Because the monoclinic crystal has two independent NarL molecules per asymmetric unit, we now have three completely independent snapshots of the NarL molecule: two from the monoclinic form and one from the orthorhombic. Comparison of these three structures shows the following: (a) The pairing of N and C domains of the NarL molecule proposed from the earlier analysis is in fact correct, although the polypeptide chain connecting domains was, and remains, disordered and not completely visible. The new structure exhibits identical relative orientation of N and C domains, and supplies some of the missing residues, leaving a gap of only seven amino acids. (b) Examination of corresponding features in the three independent NarL molecules shows that deformations in structure produced by crystal packing are negligible. (c) The "telephone receiver" model of NarL activation is confirmed. The N domain of NarL blocks the binding of DNA to the C domain that would be expected from the helix-turn-helix structure of the C domain. Hence, binding can only occur after significant displacement of N and C domains. (d) NarL monomers have a strong tendency toward dimerization involving contacts between helixes alpha 1 in the two monomers, and this may have mechanistic significance in DNA binding. Analogous involvement of helix alpha 1 in intermolecular contacts is also found in UhpA and in the CheY/CheZ complex.

NarL dimerization? Suggestive evidence from a new crystal form.,Baikalov I, Schroder I, Kaczor-Grzeskowiak M, Cascio D, Gunsalus RP, Dickerson RE Biochemistry. 1998 Mar 17;37(11):3665-76. PMID:9521685<ref>PMID:9521685</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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==See Also==
*[[Response regulator 3D structure|Response regulator 3D structure]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Escherichia coli]]
[[Category: Large Structures]]
[[Category: Baikalov I]]
[[Category: Cascio D]]
[[Category: Dickerson RE]]
[[Category: Gunsalus RP]]
[[Category: Kaczor-Grzeskowiak M]]
[[Category: Schroder I]]