View source for 3kjt


==Stimulation of the maltose transporter by a mutant sucrose binding protein gives insights into ABC transporter coupling==
<StructureSection load='3kjt' size='340' side='right'caption='[[3kjt]], [[Resolution|resolution]] 1.50&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[3kjt]] 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=3KJT OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3KJT 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]] 1.5&#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=3kjt FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3kjt OCA], [https://pdbe.org/3kjt PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=3kjt RCSB], [https://www.ebi.ac.uk/pdbsum/3kjt PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=3kjt ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/MALE_ECOLI MALE_ECOLI] Involved in the high-affinity maltose membrane transport system MalEFGK. Initial receptor for the active transport of and chemotaxis toward maltooligosaccharides.
== Evolutionary Conservation ==
[[Image:Consurf_key_small.gif|200px|right]]
Check<jmol>
  <jmolCheckbox>
    <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/kj/3kjt_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked>
    <text>to colour the structure by Evolutionary Conservation</text>
  </jmolCheckbox>
</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=3kjt ConSurf].
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== Publication Abstract from PubMed ==
The ATPase activity of the maltose transporter (MalFGK(2)) is dependent on interactions with the maltose-binding protein (MBP). To determine whether direct interactions between the translocated sugar and MalFGK(2) are important for the regulation of ATP hydrolysis, we used an MBP mutant (sMBP) that is able to bind either maltose or sucrose. We observed that maltose- and sucrose-bound sMBP stimulate equal levels of MalFGK(2) ATPase activity. Therefore, the ATPase activity of MalFGK(2) is coupled to translocation of maltose solely by interactions between MalFGK(2) and MBP. For both maltose and sucrose, the ability of sMBP to stimulate the MalFGK(2) ATPase was greatly reduced compared with wild-type MBP, indicating that the mutations in sMBP have interfered with important interactions between MBP and MalFGK(2). High resolution crystal structure analysis of sMBP shows that in the closed conformation with bound sucrose, three of four mutations are buried, and the fourth causes only a minor change in the accessible surface. In contrast, in the open form of sMBP, all of the mutations are accessible, and the main chain of Tyr(62)-Gly(69) is destabilized and occupies an alternative conformation due to the W62Y mutation. On this basis, the compromised ability of sMBP to stimulate ATP hydrolysis by MalFGK(2) is most likely due to a disruption of interactions between MalFGK(2) and the open, rather than the closed, conformation of sMBP. Modeling the open sMBP structure bound to MalFGK(2) in the transition state for ATP hydrolysis points to an important site of interaction and suggests a mechanism for coupling ATP hydrolysis to substrate translocation that is independent of the exact structure of the substrate.

Studies of the maltose transport system reveal a mechanism for coupling ATP hydrolysis to substrate translocation without direct recognition of substrate.,Gould AD, Shilton BH J Biol Chem. 2010 Apr 9;285(15):11290-6. Epub 2010 Feb 10. PMID:20147285<ref>PMID:20147285</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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==See Also==
*[[Maltose-binding protein 3D structures|Maltose-binding protein 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Escherichia coli K-12]]
[[Category: Large Structures]]
[[Category: Gould AD]]
[[Category: Shilton BH]]