View source for 4zyr


==Crystal structure of E. coli Lactose permease G46W/G262W bound to p-nitrophenyl alpha-D-galactopyranoside (alpha-NPG)==
<StructureSection load='4zyr' size='340' side='right'caption='[[4zyr]], [[Resolution|resolution]] 3.31&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4zyr]] is a 2 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=4ZYR OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4ZYR 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]] 3.312&#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=4zyr FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4zyr OCA], [https://pdbe.org/4zyr PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4zyr RCSB], [https://www.ebi.ac.uk/pdbsum/4zyr PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4zyr 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 X-ray crystal structure of a conformationally constrained mutant of the Escherichia coli lactose permease (the LacY double-Trp mutant Gly-46--&gt;Trp/Gly-262--&gt;Trp) with bound p-nitrophenyl-alpha-d-galactopyranoside (alpha-NPG), a high-affinity lactose analog, is described. With the exception of Glu-126 (helix IV), side chains Trp-151 (helix V), Glu-269 (helix VIII), Arg-144 (helix V), His-322 (helix X), and Asn-272 (helix VIII) interact directly with the galactopyranosyl ring of alpha-NPG to provide specificity, as indicated by biochemical studies and shown directly by X-ray crystallography. In contrast, Phe-20, Met-23, and Phe-27 (helix I) are within van der Waals distance of the benzyl moiety of the analog and thereby increase binding affinity nonspecifically. Thus, the specificity of LacY for sugar is determined solely by side-chain interactions with the galactopyranosyl ring, whereas affinity is increased by nonspecific hydrophobic interactions with the anomeric substituent.

Structure of LacY with an alpha-substituted galactoside: Connecting the binding site to the protonation site.,Kumar H, Finer-Moore JS, Kaback HR, Stroud RM Proc Natl Acad Sci U S A. 2015 Jul 21;112(29):9004-9. doi:, 10.1073/pnas.1509854112. Epub 2015 Jul 8. PMID:26157133<ref>PMID:26157133</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 4zyr" style="background-color:#fffaf0;"></div>

==See Also==
*[[Lactose Permease|Lactose Permease]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Escherichia coli K-12]]
[[Category: Large Structures]]
[[Category: Finer-Moore JS]]
[[Category: Kaback HR]]
[[Category: Kumar H]]
[[Category: Stroud RM]]