2awn

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[[Image:2awn.gif|left|200px]]<br /><applet load="2awn" size="350" color="white" frame="true" align="right" spinBox="true"
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[[Image:2awn.gif|left|200px]]
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caption="2awn, resolution 2.30&Aring;" />
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'''Crystal structure of the ADP-Mg-bound E. Coli MALK (Crystallized with ATP-Mg)'''<br />
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{{Structure
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|PDB= 2awn |SIZE=350|CAPTION= <scene name='initialview01'>2awn</scene>, resolution 2.30&Aring;
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|SITE=
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|LIGAND= <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene> and <scene name='pdbligand=ADP:ADENOSINE-5'-DIPHOSPHATE'>ADP</scene>
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|ACTIVITY= [http://en.wikipedia.org/wiki/Maltose-transporting_ATPase Maltose-transporting ATPase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.6.3.19 3.6.3.19]
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|GENE= malK ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=562 Escherichia coli])
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}}
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'''Crystal structure of the ADP-Mg-bound E. Coli MALK (Crystallized with ATP-Mg)'''
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==Overview==
==Overview==
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==About this Structure==
==About this Structure==
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2AWN is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with <scene name='pdbligand=MG:'>MG</scene> and <scene name='pdbligand=ADP:'>ADP</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Maltose-transporting_ATPase Maltose-transporting ATPase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.6.3.19 3.6.3.19] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2AWN OCA].
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2AWN is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2AWN OCA].
==Reference==
==Reference==
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ATP hydrolysis is required to reset the ATP-binding cassette dimer into the resting-state conformation., Lu G, Westbrooks JM, Davidson AL, Chen J, Proc Natl Acad Sci U S A. 2005 Dec 13;102(50):17969-74. Epub 2005 Dec 2. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=16326809 16326809]
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ATP hydrolysis is required to reset the ATP-binding cassette dimer into the resting-state conformation., Lu G, Westbrooks JM, Davidson AL, Chen J, Proc Natl Acad Sci U S A. 2005 Dec 13;102(50):17969-74. Epub 2005 Dec 2. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/16326809 16326809]
[[Category: Escherichia coli]]
[[Category: Escherichia coli]]
[[Category: Maltose-transporting ATPase]]
[[Category: Maltose-transporting ATPase]]
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[[Category: atp-binding cassette]]
[[Category: atp-binding cassette]]
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''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 16:31:45 2008''
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''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Mar 20 15:54:46 2008''

Revision as of 13:54, 20 March 2008


PDB ID 2awn

Drag the structure with the mouse to rotate
, resolution 2.30Å
Ligands: and
Gene: malK (Escherichia coli)
Activity: Maltose-transporting ATPase, with EC number 3.6.3.19
Coordinates: save as pdb, mmCIF, xml



Crystal structure of the ADP-Mg-bound E. Coli MALK (Crystallized with ATP-Mg)


Overview

ATP-binding cassette (ABC) transporters couple ATP binding and hydrolysis to the movement of substances across the membrane; conformational changes clearly play an important role in the transporter mechanism. Previously, we have shown that a dimer of MalK, the ATPase subunit of the maltose transporter from Escherichia coli, undergoes a tweezers-like motion in a transport cycle. The MalK monomer consists of an N-terminal nucleotide binding domain and a C-terminal regulatory domain. The two nucleotide-binding domains in a dimer are either open or closed, depending on whether ATP is present, while the regulatory domains maintain contacts to hold the dimer together. In this work, the structure of MalK in a posthydrolysis state is presented, obtained by cocrystallizing MalK with ATP-Mg(2+). ATP was hydrolyzed in the crystallization drop, and ADP-Mg(2+) was found in the resulting crystal structure. In contrast to the ATP-bound form where two ATP molecules are buried in a closed interface between the nucleotide-binding domains, the two nucleotide-binding domains of the ADP-bound form are open, indicating that ADP, unlike ATP, cannot stabilize the closed form. This conclusion is further supported by oligomerization studies of MalK in solution. At low protein concentrations, ATP promotes dimerization of MalK, whereas ADP does not. The structures of dimeric MalK in the nucleotide-free, ATP-bound, and ADP-bound forms provide a framework for understanding the nature of the conformational changes that occur in an ATP-binding cassette transporter hydrolysis cycle, as well as how conformational changes in MalK are coupled to solute transport.

About this Structure

2AWN is a Single protein structure of sequence from Escherichia coli. Full crystallographic information is available from OCA.

Reference

ATP hydrolysis is required to reset the ATP-binding cassette dimer into the resting-state conformation., Lu G, Westbrooks JM, Davidson AL, Chen J, Proc Natl Acad Sci U S A. 2005 Dec 13;102(50):17969-74. Epub 2005 Dec 2. PMID:16326809

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