View source for 3tch


==Crystal structure of E. coli OppA in an open conformation==
<StructureSection load='3tch' size='340' side='right'caption='[[3tch]], [[Resolution|resolution]] 1.98&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[3tch]] 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=3TCH OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3TCH 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]] 1.98&#8491;</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=3tch FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3tch OCA], [https://pdbe.org/3tch PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=3tch RCSB], [https://www.ebi.ac.uk/pdbsum/3tch PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=3tch ProSAT]</span></td></tr>
</table>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The Escherichia coli peptide binding protein OppA is an essential component of the oligopeptide transporter Opp. Based on studies on its orthologue from Salmonella typhimurium, it has been proposed that OppA binds peptides between two and five amino acids long, with no apparent sequence selectivity. Here, we studied peptide binding to E. coli OppA directly and show that the protein has an unexpected preference for basic peptides. OppA was expressed in the periplasm, where it bound to available peptides. The protein was purified in complex with tightly bound peptides. The crystal structure (up to 2.0 A) of OppA liganded with the peptides indicated that the protein has a preference for peptides containing a lysine. Mass spectrometry analysis of the bound peptides showed that peptides between two and five amino acids long bind to the protein and indeed hinted at a preference for positively charged peptides. The preference of OppA for peptides with basic residues, in particular lysines, was corroborated by binding studies with peptides of defined sequence using isothermal titration calorimetry and intrinsic protein fluorescence titration. The protein bound tripeptides and tetrapeptides containing positively charged residues with high affinity, whereas related peptides without lysines/arginines were bound with low affinity. A structure of OppA in an open conformation in the absence of ligands was also determined to 2.0 A, revealing that the initial binding site displays a negative surface charge, consistent with the observed preference for positively charged peptides. Taken together, E. coli OppA appears to have a preference for basic peptides.

Escherichia coli peptide binding protein OppA has a preference for positively charged peptides.,Klepsch MM, Kovermann M, Low C, Balbach J, Permentier HP, Fusetti F, de Gier JW, Slotboom DJ, Berntsson RP J Mol Biol. 2011 Nov 18;414(1):75-85. Epub 2011 Oct 1. PMID:21983341<ref>PMID:21983341</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 3tch" style="background-color:#fffaf0;"></div>

==See Also==
*[[ABC transporter 3D structures|ABC transporter 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Escherichia coli K-12]]
[[Category: Large Structures]]
[[Category: Balbach J]]
[[Category: Berntsson RP-A]]
[[Category: Klepsch MM]]
[[Category: Kovermann M]]
[[Category: Low C]]
[[Category: Slotboom DJ]]
[[Category: De Gier JW]]