View source for 4yah


==Crystal Structure of the Methionine Binding Protein, MetQ==
<StructureSection load='4yah' size='340' side='right'caption='[[4yah]], [[Resolution|resolution]] 1.60&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4yah]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Escherichia_coli_K-12 Escherichia coli K-12]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4YAH OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4YAH FirstGlance]. <br>
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=MET:METHIONINE'>MET</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=4yah FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4yah OCA], [https://pdbe.org/4yah PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4yah RCSB], [https://www.ebi.ac.uk/pdbsum/4yah PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4yah ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/METQ_ECOLI METQ_ECOLI] This protein is a component of a D-methionine permease, a binding protein-dependent, ATP-driven transport system.<ref>PMID:12169620</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Despite the ubiquitous role of ATP Binding Cassette (ABC) importers in nutrient uptake, only the E. coli maltose and vitamin B12 ABC transporters have been structurally characterized in multiple conformations relevant to the alternating access transport mechanism. To complement our previous structure determination of the E. coli MetNI methionine importer in the inward facing conformation (Kadaba et al. (2008) Science 321, 250-253), we have explored conditions stabilizing the outward facing conformation. Using two variants, the Walker B E166Q mutation with ATP+EDTA to stabilize MetNI in the ATP-bound conformation and the N229A variant of the binding protein MetQ, shown in this work to disrupt methionine binding, a high affinity MetNIQ complex was formed with a dissociation constant measured to be 27 nM. Using wild type MetQ containing a co-purified methionine (for which the crystal structure is reported at 1.6 A resolution), the dissociation constant for complex formation with MetNI is measured to be ~40-fold weaker, indicating that complex formation lowers the affinity of MetQ for methionine by this amount. Preparation of a stable MetNIQ complex is an essential step towards the crystallographic analysis of the outward facing conformation, a key intermediate in the uptake of methionine by this transport system.

The contribution of methionine to the stability of the Escherichia coli MetNIQ ABC transporter-substrate binding protein complex.,Nguyen PT, Li QW, Kadaba NS, Lai JY, Yang JG, Rees DC Biol Chem. 2015 Mar 24. pii:, /j/bchm.just-accepted/hsz-2015-0131/hsz-2015-0131.xml. doi:, 10.1515/hsz-2015-0131. PMID:25803078<ref>PMID:25803078</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 4yah" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Escherichia coli K-12]]
[[Category: Large Structures]]
[[Category: Kadaba NS]]
[[Category: Kaiser JT]]
[[Category: Lai JY]]
[[Category: Rees DC]]