1xef: Difference between revisions
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[[Image:1xef.gif|left|200px]] | [[Image:1xef.gif|left|200px]] | ||
'''Crystal structure of the ATP/Mg2+ bound composite dimer of HlyB-NBD''' | {{Structure | ||
|PDB= 1xef |SIZE=350|CAPTION= <scene name='initialview01'>1xef</scene>, resolution 2.50Å | |||
|SITE= | |||
|LIGAND= <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene> and <scene name='pdbligand=ATP:ADENOSINE-5'-TRIPHOSPHATE'>ATP</scene> | |||
|ACTIVITY= | |||
|GENE= | |||
}} | |||
'''Crystal structure of the ATP/Mg2+ bound composite dimer of HlyB-NBD''' | |||
==Overview== | ==Overview== | ||
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==About this Structure== | ==About this Structure== | ||
1XEF is a [ | 1XEF 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=1XEF OCA]. | ||
==Reference== | ==Reference== | ||
H662 is the linchpin of ATP hydrolysis in the nucleotide-binding domain of the ABC transporter HlyB., Zaitseva J, Jenewein S, Jumpertz T, Holland IB, Schmitt L, EMBO J. 2005 Jun 1;24(11):1901-10. Epub 2005 May 12. PMID:[http:// | H662 is the linchpin of ATP hydrolysis in the nucleotide-binding domain of the ABC transporter HlyB., Zaitseva J, Jenewein S, Jumpertz T, Holland IB, Schmitt L, EMBO J. 2005 Jun 1;24(11):1901-10. Epub 2005 May 12. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/15889153 15889153] | ||
[[Category: Escherichia coli]] | [[Category: Escherichia coli]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
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[[Category: haemolysin b]] | [[Category: haemolysin b]] | ||
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Mar 20 15:08:40 2008'' | ||
Revision as of 16:08, 20 March 2008
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| Coordinates: | save as pdb, mmCIF, xml | ||||||
Crystal structure of the ATP/Mg2+ bound composite dimer of HlyB-NBD
OverviewOverview
The ABC transporter HlyB is a central element of the HlyA secretion machinery, a paradigm of Type I secretion. Here, we describe the crystal structure of the HlyB-NBD (nucleotide-binding domain) with H662 replaced by Ala in complex with ATP/Mg2+. The dimer shows a composite architecture, in which two intact ATP molecules are bound at the interface of the Walker A motif and the C-loop, provided by the two monomers. ATPase measurements confirm that H662 is essential for activity. Based on these data, we propose a model in which E631 and H662, highly conserved among ABC transporters, form a catalytic dyad. Here, H662 acts as a 'linchpin', holding together all required parts of a complicated network of interactions between ATP, water molecules, Mg2+, and amino acids both in cis and trans, necessary for intermonomer communication. Based on biochemical experiments, we discuss the hypothesis that substrate-assisted catalysis, rather than general base catalysis might operate in ABC-ATPases.
About this StructureAbout this Structure
1XEF is a Single protein structure of sequence from Escherichia coli. Full crystallographic information is available from OCA.
ReferenceReference
H662 is the linchpin of ATP hydrolysis in the nucleotide-binding domain of the ABC transporter HlyB., Zaitseva J, Jenewein S, Jumpertz T, Holland IB, Schmitt L, EMBO J. 2005 Jun 1;24(11):1901-10. Epub 2005 May 12. PMID:15889153
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