View source for 6c9w


==Crystal Structure of a ligand bound LacY/Nanobody Complex==
<StructureSection load='6c9w' size='340' side='right'caption='[[6c9w]], [[Resolution|resolution]] 3.00&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[6c9w]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Escherichia_coli_K-12 Escherichia coli K-12] and [https://en.wikipedia.org/wiki/Lama_glama Lama glama]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6C9W OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6C9W 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]] 3&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=9PG:4-NITROPHENYL+ALPHA-D-GALACTOPYRANOSIDE'>9PG</scene>, <scene name='pdbligand=BNG:B-NONYLGLUCOSIDE'>BNG</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=6c9w FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6c9w OCA], [https://pdbe.org/6c9w PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6c9w RCSB], [https://www.ebi.ac.uk/pdbsum/6c9w PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6c9w ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/LACY_ECOLI LACY_ECOLI] Responsible for transport of beta-galactosides into the cell, with the concomitant import of a proton (symport system).
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The lactose permease of Escherichia coli (LacY), a dynamic polytopic membrane transport protein, catalyzes galactoside/H(+) symport and operates by an alternating access mechanism that exhibits multiple conformations, the distribution of which is altered by sugar-binding. Camelid nanobodies were made against a double-mutant Gly46 --&gt; Trp/Gly262 --&gt; Trp (LacYWW) that produces an outward-open conformation, as opposed to the cytoplasmic open-state crystal structure of WT LacY. Nanobody 9047 (Nb9047) stabilizes WT LacY in a periplasmic-open conformation. Here, we describe the X-ray crystal structure of a complex between LacYWW, the high-affinity substrate analog 4-nitrophenyl-alpha-d-galactoside (NPG), and Nb9047 at 3-A resolution. The present crystal structure demonstrates that Nb9047 binds to the periplasmic face of LacY, primarily to the C-terminal six-helical bundle, while a flexible loop of the Nb forms a bridge between the N- and C-terminal halves of LacY across the periplasmic vestibule. The bound Nb partially covers the vestibule, yet does not affect the on-rates or off-rates for the substrate binding to LacYWW, which implicates dynamic flexibility of the Nb-LacYWW complex. Nb9047-binding neither changes the overall structure of LacYWW with bound NPG, nor the positions of side chains comprising the galactoside-binding site. The current NPG-bound structure exhibits a more occluded periplasmic vestibule than seen in a previous structure of a (different Nb) apo-LacYWW/Nb9039 complex that we argue is caused by sugar-binding, with major differences located at the periplasmic ends of transmembrane helices in the N-terminal half of LacY.

Crystal Structure of a ligand-bound LacY-Nanobody Complex.,Kumar H, Finer-Moore JS, Jiang X, Smirnova I, Kasho V, Pardon E, Steyaert J, Kaback HR, Stroud RM Proc Natl Acad Sci U S A. 2018 Aug 14. pii: 1801774115. doi:, 10.1073/pnas.1801774115. PMID:30108145<ref>PMID:30108145</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 6c9w" style="background-color:#fffaf0;"></div>

==See Also==
*[[Antibody 3D structures|Antibody 3D structures]]
*[[Lactose Permease|Lactose Permease]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Escherichia coli K-12]]
[[Category: Lama glama]]
[[Category: Large Structures]]
[[Category: Finer-Moore JS]]
[[Category: Jiang X]]
[[Category: Kaback HR]]
[[Category: Kasho V]]
[[Category: Kumar H]]
[[Category: Pardon E]]
[[Category: Smirnova I]]
[[Category: Steyaert J]]
[[Category: Stroud RM]]