View source for 4v44


==E. COLI (lacZ) BETA-GALACTOSIDASE IN COMPLEX WITH 2-F-LACTOSE==
<StructureSection load='4v44' size='340' side='right'caption='[[4v44]], [[Resolution|resolution]] 2.70&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4v44]] is a 16 chain structure with sequence from [https://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. This structure supersedes the now removed PDB entries [http://oca.weizmann.ac.il/oca-bin/send-pdb?obs=1&id=1jyy 1jyy] and [http://oca.weizmann.ac.il/oca-bin/send-pdb?obs=1&id=1jyz 1jyz]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4V44 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4V44 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]] 2.7&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=2FG:2-FLUORO-2-DEOXY-BETA-D-GALACTOPYRANOSE'>2FG</scene>, <scene name='pdbligand=BGC:BETA-D-GLUCOSE'>BGC</scene>, <scene name='pdbligand=CME:S,S-(2-HYDROXYETHYL)THIOCYSTEINE'>CME</scene>, <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene>, <scene name='pdbligand=NA:SODIUM+ION'>NA</scene>, <scene name='pdbligand=PRD_900064:2-deoxy-2-fluoro-beta-lactose'>PRD_900064</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=4v44 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4v44 OCA], [https://pdbe.org/4v44 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4v44 RCSB], [https://www.ebi.ac.uk/pdbsum/4v44 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4v44 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/BGAL_ECOLI BGAL_ECOLI] 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The structures of a series of complexes designed to mimic intermediates along the reaction coordinate for beta-galactosidase are presented. These complexes clarify and enhance previous proposals regarding the catalytic mechanism. The nucleophile, Glu537, is seen to covalently bind to the galactosyl moiety. Of the two potential acids, Mg(2+) and Glu461, the latter is in better position to directly assist in leaving group departure, suggesting that the metal ion acts in a secondary role. A sodium ion plays a part in substrate binding by directly ligating the galactosyl 6-hydroxyl. The proposed reaction coordinate involves the movement of the galactosyl moiety deep into the active site pocket. For those ligands that do bind deeply there is an associated conformational change in which residues within loop 794-804 move up to 10 A closer to the site of binding. In some cases this can be inhibited by the binding of additional ligands. The resulting restricted access to the intermediate helps to explain why allolactose, the natural inducer for the lac operon, is the preferred product of transglycosylation.

A structural view of the action of Escherichia coli (lacZ) beta-galactosidase.,Juers DH, Heightman TD, Vasella A, McCarter JD, Mackenzie L, Withers SG, Matthews BW Biochemistry. 2001 Dec 11;40(49):14781-94. PMID:11732897<ref>PMID:11732897</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 4v44" style="background-color:#fffaf0;"></div>

==See Also==
*[[Galactosidase 3D structures|Galactosidase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Escherichia coli]]
[[Category: Large Structures]]
[[Category: Juers DH]]
[[Category: Matthews BW]]
[[Category: McCarter JD]]
[[Category: Withers SG]]