1xxb

<table><tr><td colspan='2'>[[1xxb]] is a 6 chain structure with sequence from [http://en.wikipedia.org/wiki/Ecoli Ecoli]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1XXB OCA]. For a <b>guided tour on the structure components</b> use [http://proteopedia.org/fgij/fg.htm?mol=1XXB FirstGlance]. <br>

</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=ARG:ARGININE'>ARG</scene></td></tr>

<tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">T7 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=83333 ECOLI])</td></tr>

<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://proteopedia.org/fgij/fg.htm?mol=1xxb FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1xxb OCA], [http://pdbe.org/1xxb PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=1xxb RCSB], [http://www.ebi.ac.uk/pdbsum/1xxb PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=1xxb ProSAT]</span></td></tr>

[[http://www.uniprot.org/uniprot/ARGR_ECOLI ARGR_ECOLI]] Negatively controls the expression of the four operons of arginine biosynthesis in addition to the carAB operon. Predominantly interacts with A/T residues in ARG boxes. It also binds to a specific site in cer locus. Thus it is essential for cer-mediated site-specific recombination in ColE1. It is necessary for monomerization of the plasmid ColE1.

<div style="background-color:#fffaf0;">

== Publication Abstract from PubMed ==

The structure of the oligomerization and L-arginine binding domain of the Escherichia coli arginine repressor (ArgR) has been determined using X-ray diffraction methods at 2.2 A resolution with bound arginine and at 2.8 A in the unliganded form. The oligomeric core is a 3-fold rotationally symmetric hexamer formed from six identical subunits corresponding to the 77 C-terminal residues (80 to 156) of ArgR. Each subunit has an alpha/beta fold containing a four-stranded antiparallel beta-sheet and two antiparallel alpha-helices. The hexamer is formed from two trimers, each with tightly packed hydrophobic cores. In the absence of arginine, the trimers stack back-to-back through a dyad-symmetric, sparsely packed hydrophobic interface. Six molecules of arginine bind at the trimer-trimer interface, each making ten hydrogen bonds to the protein including a direct ion pair that crosslinks the two protein trimers. Solution experiments with wild-type ArgR and oligomerization domain indicate that the hexameric form is greatly stabilized upon arginine binding. The crystal structures and solution experiments together suggest possible mechanisms of how arginine activates ArgR to bind to its DNA targets and provides a stereochemical basis for interpreting the results of mutagenesis and biochemical experiments with ArgR.

Structure of the oligomerization and L-arginine binding domain of the arginine repressor of Escherichia coli.,Van Duyne GD, Ghosh G, Maas WK, Sigler PB J Mol Biol. 1996 Feb 23;256(2):377-91. PMID:8594204<ref>PMID:8594204</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>

</div>

<div class="pdbe-citations 1xxb" style="background-color:#fffaf0;"></div>

== References ==

<references/>

[[Category: Ecoli]]

[[Category: Duyne, G D.Van]]

[[Category: Ghosh, G]]

[[Category: Maas, W K]]

[[Category: Sigler, P B]]