2npd: Difference between revisions
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[[Image:2npd.gif|left|200px]] | [[Image:2npd.gif|left|200px]] | ||
'''An unusual twin-His arrangement in the pore of ammonia channels is essential for substrate conductance''' | {{Structure | ||
|PDB= 2npd |SIZE=350|CAPTION= <scene name='initialview01'>2npd</scene>, resolution 2.10Å | |||
|SITE= | |||
|LIGAND= <scene name='pdbligand=ACT:ACETATE+ION'>ACT</scene> and <scene name='pdbligand=IMD:IMIDAZOLE'>IMD</scene> | |||
|ACTIVITY= | |||
|GENE= amtB ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=562 Escherichia coli]) | |||
}} | |||
'''An unusual twin-His arrangement in the pore of ammonia channels is essential for substrate conductance''' | |||
==Overview== | ==Overview== | ||
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==About this Structure== | ==About this Structure== | ||
2NPD is a [ | 2NPD 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=2NPD OCA]. | ||
==Reference== | ==Reference== | ||
An unusual twin-his arrangement in the pore of ammonia channels is essential for substrate conductance., Javelle A, Lupo D, Zheng L, Li XD, Winkler FK, Merrick M, J Biol Chem. 2006 Dec 22;281(51):39492-8. Epub 2006 Oct 12. PMID:[http:// | An unusual twin-his arrangement in the pore of ammonia channels is essential for substrate conductance., Javelle A, Lupo D, Zheng L, Li XD, Winkler FK, Merrick M, J Biol Chem. 2006 Dec 22;281(51):39492-8. Epub 2006 Oct 12. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/17040913 17040913] | ||
[[Category: Escherichia coli]] | [[Category: Escherichia coli]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
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[[Category: membrane protein]] | [[Category: membrane protein]] | ||
''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 17:49:19 2008'' | ||
Revision as of 18:49, 20 March 2008
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| , resolution 2.10Å | |||||||
|---|---|---|---|---|---|---|---|
| Ligands: | and | ||||||
| Gene: | amtB (Escherichia coli) | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
An unusual twin-His arrangement in the pore of ammonia channels is essential for substrate conductance
OverviewOverview
Amt proteins constitute a class of ubiquitous integral membrane proteins that mediate movement of ammonium across cell membranes. They are homotrimers, in which each subunit contains a narrow pore through which substrate transport occurs. Two conserved histidine residues in the pore have been proposed to be necessary for ammonia conductance. By analyzing 14 engineered polar and non-polar variants of these histidines, in Escherichia coli AmtB, we show that both histidines are absolutely required for optimum substrate conductance. Crystal structures of variants confirm that substitution of the histidine residues does not affect AmtB structure. In a subgroup of Amt proteins, found only in fungi, one of the histidines is replaced by glutamate. The equivalent substitution in E. coli AmtB is partially active, and the structure of this variant suggests that the glutamate side chain can make similar interactions to those made by histidine.
About this StructureAbout this Structure
2NPD is a Single protein structure of sequence from Escherichia coli. Full crystallographic information is available from OCA.
ReferenceReference
An unusual twin-his arrangement in the pore of ammonia channels is essential for substrate conductance., Javelle A, Lupo D, Zheng L, Li XD, Winkler FK, Merrick M, J Biol Chem. 2006 Dec 22;281(51):39492-8. Epub 2006 Oct 12. PMID:17040913
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