1u9l
From Proteopedia
(New page: 200px<br /><applet load="1u9l" size="450" color="white" frame="true" align="right" spinBox="true" caption="1u9l, resolution 1.90Å" /> '''Structural basis for...) |
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| - | [[Image:1u9l.gif|left|200px]]<br /><applet load="1u9l" size=" | + | [[Image:1u9l.gif|left|200px]]<br /><applet load="1u9l" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1u9l, resolution 1.90Å" /> | caption="1u9l, resolution 1.90Å" /> | ||
'''Structural basis for a NusA- protein N interaction'''<br /> | '''Structural basis for a NusA- protein N interaction'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The C terminus of transcription factor NusA from Escherichia coli | + | The C terminus of transcription factor NusA from Escherichia coli comprises two repeat units, which bind during antitermination to protein N from phage lambda. To delineate the structural basis of the NusA-lambdaN interaction, we attempted to crystallize the NusA C-terminal repeats in complex with a lambdaN peptide (residues 34-47). The two NusA domains became proteolytically separated during crystallization, and crystals contained two copies of the first repeat unit in contact with a single lambdaN fragment. The NusA modules employ identical regions to contact the peptide but approach the ligand from opposite sides. In contrast to the alpha-helical conformation of the lambdaN N terminus in complex with boxB RNA, residues 34-40 of lambdaN remain extended upon interaction with NusA. Mutational analyses indicated that only one of the observed NusA-lambdaN interaction modes is biologically significant, supporting an equimolar ratio of NusA and lambdaN in antitermination complexes. Solution studies indicated that additional interactions are fostered by the second NusA repeat unit, consistent with known compensatory mutations in NusA and lambdaN. Contrary to the RNA polymerase alpha subunit, lambdaN binding does not stimulate RNA interaction of NusA. The results demonstrate that lambdaN serves as a scaffold to closely oppose NusA and the mRNA in antitermination complexes. |
==About this Structure== | ==About this Structure== | ||
| - | 1U9L 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 AU as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http:// | + | 1U9L 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=AU:'>AU</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1U9L OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Bacher, A.]] | [[Category: Bacher, A.]] | ||
[[Category: Bonin, I.]] | [[Category: Bonin, I.]] | ||
| - | [[Category: Bourenkov, G | + | [[Category: Bourenkov, G P.]] |
[[Category: Huber, R.]] | [[Category: Huber, R.]] | ||
[[Category: Muehlberger, R.]] | [[Category: Muehlberger, R.]] | ||
[[Category: Richter, G.]] | [[Category: Richter, G.]] | ||
| - | [[Category: Wahl, M | + | [[Category: Wahl, M C.]] |
[[Category: AU]] | [[Category: AU]] | ||
[[Category: escherichia coli nusa]] | [[Category: escherichia coli nusa]] | ||
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[[Category: x-ray crystallography]] | [[Category: x-ray crystallography]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 15:22:08 2008'' |
Revision as of 13:22, 21 February 2008
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Structural basis for a NusA- protein N interaction
Overview
The C terminus of transcription factor NusA from Escherichia coli comprises two repeat units, which bind during antitermination to protein N from phage lambda. To delineate the structural basis of the NusA-lambdaN interaction, we attempted to crystallize the NusA C-terminal repeats in complex with a lambdaN peptide (residues 34-47). The two NusA domains became proteolytically separated during crystallization, and crystals contained two copies of the first repeat unit in contact with a single lambdaN fragment. The NusA modules employ identical regions to contact the peptide but approach the ligand from opposite sides. In contrast to the alpha-helical conformation of the lambdaN N terminus in complex with boxB RNA, residues 34-40 of lambdaN remain extended upon interaction with NusA. Mutational analyses indicated that only one of the observed NusA-lambdaN interaction modes is biologically significant, supporting an equimolar ratio of NusA and lambdaN in antitermination complexes. Solution studies indicated that additional interactions are fostered by the second NusA repeat unit, consistent with known compensatory mutations in NusA and lambdaN. Contrary to the RNA polymerase alpha subunit, lambdaN binding does not stimulate RNA interaction of NusA. The results demonstrate that lambdaN serves as a scaffold to closely oppose NusA and the mRNA in antitermination complexes.
About this Structure
1U9L is a Single protein structure of sequence from Escherichia coli with as ligand. Full crystallographic information is available from OCA.
Reference
Structural basis for the interaction of Escherichia coli NusA with protein N of phage lambda., Bonin I, Muhlberger R, Bourenkov GP, Huber R, Bacher A, Richter G, Wahl MC, Proc Natl Acad Sci U S A. 2004 Sep 21;101(38):13762-7. Epub 2004 Sep 13. PMID:15365170
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