View source for 4xxh


==TREHALOSE REPRESSOR FROM ESCHERICHIA COLI==
<StructureSection load='4xxh' size='340' side='right'caption='[[4xxh]], [[Resolution|resolution]] 2.40&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4xxh]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Escherichia_coli_K-12 Escherichia coli K-12]. This structure supersedes the now removed PDB entry [http://oca.weizmann.ac.il/oca-bin/send-pdb?obs=1&id=1byk 1byk]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4XXH OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4XXH 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]] 2.4&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=G6P:ALPHA-D-GLUCOSE-6-PHOSPHATE'>G6P</scene>, <scene name='pdbligand=GLC:ALPHA-D-GLUCOSE'>GLC</scene>, <scene name='pdbligand=PRD_900039:trehalose-6-phosphate'>PRD_900039</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=4xxh FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4xxh OCA], [https://pdbe.org/4xxh PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4xxh RCSB], [https://www.ebi.ac.uk/pdbsum/4xxh PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4xxh ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/TRER_ECOLI TRER_ECOLI] Repressor of the treBC operon. Binds trehalose 6-phosphate as an inducer.
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The crystal structure of the Escherichia coli trehalose repressor (TreR) in a complex with its inducer trehalose-6-phosphate was determined by the method of multiple isomorphous replacement (MIR) at 2.5 A resolution, followed by the structure determination of TreR in a complex with its noninducer trehalose at 3.1 A resolution. The model consists of residues 61 to 315 comprising the effector binding domain, which forms a dimer as in other members of the LacI family. This domain is composed of two similar subdomains each consisting of a central beta-sheet sandwiched between alpha-helices. The effector binding pocket is at the interface of these subdomains. In spite of different physiological functions, the crystal structures of the two complexes of TreR turned out to be virtually identical to each other with the conformation being similar to those of the effector binding domains of the LacI and PurR in complex with their effector molecules. According to the crystal structure, the noninducer trehalose binds to a similar site as the trehalose portion of trehalose-6-phosphate. The binding affinity for the former is lower than for the latter. The noninducer trehalose thus binds competitively to the repressor. Unlike the phosphorylated inducer molecule, it is incapable of blocking the binding of the repressor headpiece to its operator DNA. The ratio of the concentrations of trehalose-6-phosphate and trehalose thus is used to switch between the two alternative metabolic uses of trehalose as an osmoprotectant and as a carbon source.

Crystal structure of the effector-binding domain of the trehalose-repressor of Escherichia coli, a member of the LacI family, in its complexes with inducer trehalose-6-phosphate and noninducer trehalose.,Hars U, Horlacher R, Boos W, Welte W, Diederichs K Protein Sci. 1998 Dec;7(12):2511-21. PMID:9865945<ref>PMID:9865945</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 4xxh" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Escherichia coli K-12]]
[[Category: Large Structures]]
[[Category: Boos W]]
[[Category: Bricogne G]]
[[Category: Diederichs K]]
[[Category: Hars U]]
[[Category: Horlacher R]]
[[Category: Smart OS]]
[[Category: Welte W]]