View source for 2lcv


==Structure of the Cytidine Repressor DNA-Binding Domain; an alternate calculation==
<StructureSection load='2lcv' size='340' side='right'caption='[[2lcv]]' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[2lcv]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Escherichia_coli_K-12 Escherichia coli K-12]. Full experimental information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2LCV OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2LCV FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Solution NMR</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=2lcv FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2lcv OCA], [https://pdbe.org/2lcv PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2lcv RCSB], [https://www.ebi.ac.uk/pdbsum/2lcv PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2lcv ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/CYTR_ECOLI CYTR_ECOLI] This protein negatively controls the transcription initiation of genes such as deoCABD, udp, and cdd encoding catabolizing enzymes and nupC, nupG, and tsx encoding transporting and pore-forming proteins. Binds cytidine and adenosine as effectors.
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== Publication Abstract from PubMed ==
The cytidine repressor (CytR) is a member of the LacR family of bacterial repressors with distinct functional features. The Escherichia coli CytR regulon comprises nine operons whose palindromic operators vary in both sequence and, most significantly, in spacing between the recognition half-sites. This suggests a strong likelihood that protein folding would be coupled to DNA binding as a mechanism to accommodate the variety of different operator architectures to which CytR targets. Such coupling is a common feature of sequence-specific DNA-binding proteins including the LacR family repressors; however, there are no significant structural rearrangements upon DNA binding within the three-helix DNA-binding domains (DBDs) studied to date. We used NMR spectroscopy to characterize the CytR DBD free in solution and to determine the high-resolution structure of a CytR DBD monomer bound specifically to one DNA half-site of the uridine phosphorylase (udp) operator. We find that the free DBD populates multiple distinct conformations distinguished by up to four sets of NMR peaks per residue. This structural heterogeneity is previously unknown in the LacR family. These stable structures coalesce into a single, more stable udp-bound form that features a three-helix bundle containing a canonical helix-turn-helix motif. However, this structure differs from all other LacR family members whose structures are known with regard to the packing of the helices and consequently their relative orientations. Aspects of CytR activity are unique among repressors; we identify here structural properties that are also distinct and that might underlie the different functional properties.

Multiple Conformations of the Cytidine Repressor DNA-Binding Domain Coalesce to One Upon Recognition of a Specific DNA Surface.,Moody CL, Tretyachenko-Ladokhina V, Laue TM, Senear DF, Cocco MJ Biochemistry. 2011 Jun 21. PMID:21688840<ref>PMID:21688840</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 2lcv" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Escherichia coli K-12]]
[[Category: Large Structures]]
[[Category: Cocco MJ]]
[[Category: Moody CL]]
[[Category: Senear DF]]
[[Category: Tretyachenko-Ladokhina V]]