View source for 6cvl


==Crystal structure of the Escherichia coli ATPgS-bound MetNI methionine ABC transporter in complex with its MetQ binding protein==
<StructureSection load='6cvl' size='340' side='right'caption='[[6cvl]], [[Resolution|resolution]] 2.95&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[6cvl]] is a 5 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=6CVL OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6CVL 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]] 2.953&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=AGS:PHOSPHOTHIOPHOSPHORIC+ACID-ADENYLATE+ESTER'>AGS</scene>, <scene name='pdbligand=HG:MERCURY+(II)+ION'>HG</scene>, <scene name='pdbligand=IOD:IODIDE+ION'>IOD</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=6cvl FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6cvl OCA], [https://pdbe.org/6cvl PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6cvl RCSB], [https://www.ebi.ac.uk/pdbsum/6cvl PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6cvl ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/METN_ECOLI METN_ECOLI] Part of the ABC transporter complex MetNIQ involved in methionine import. Responsible for energy coupling to the transport system (Probable). It has also been shown to be involved in formyl-L-methionine transport.<ref>PMID:12169620</ref> <ref>PMID:12819857</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The Escherichia coli methionine ABC transporter MetNI exhibits both high-affinity transport toward l-methionine and broad specificity toward methionine derivatives, including d-methionine. In this work, we characterize the transport of d-methionine derivatives by the MetNI transporter. Unexpectedly, the N229A substrate-binding deficient variant of the cognate binding protein MetQ was found to support high MetNI transport activity toward d-selenomethionine. We determined the crystal structure at 2.95 A resolution of the ATPgammaS-bound MetNIQ complex in the outward-facing conformation with the N229A apo MetQ variant. This structure revealed conformational changes in MetQ providing substrate access through the binding protein to the transmembrane translocation pathway. MetQ likely mediates uptake of methionine derivatives through two mechanisms: in the methionine-bound form delivering substrate from the periplasm to the transporter (the canonical mechanism) and in the apo form by facilitating ligand binding when complexed to the transporter (the noncanonical mechanism). This dual role for substrate-binding proteins is proposed to provide a kinetic strategy for ABC transporters to transport both high- and low-affinity substrates present in a physiological concentration range.

Noncanonical role for the binding protein in substrate uptake by the MetNI methionine ATP Binding Cassette (ABC) transporter.,Nguyen PT, Lai JY, Lee AT, Kaiser JT, Rees DC Proc Natl Acad Sci U S A. 2018 Nov 6;115(45):E10596-E10604. doi:, 10.1073/pnas.1811003115. Epub 2018 Oct 23. PMID:30352853<ref>PMID:30352853</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 6cvl" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Escherichia coli K-12]]
[[Category: Large Structures]]
[[Category: Kaiser JT]]
[[Category: Nguyen PT]]
[[Category: Rees DC]]