2a0i
From Proteopedia
(New page: 200px<br /><applet load="2a0i" size="450" color="white" frame="true" align="right" spinBox="true" caption="2a0i, resolution 2.72Å" /> '''F Factor TraI Relaxa...) |
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| - | [[Image:2a0i.gif|left|200px]]<br /><applet load="2a0i" size=" | + | [[Image:2a0i.gif|left|200px]]<br /><applet load="2a0i" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="2a0i, resolution 2.72Å" /> | caption="2a0i, resolution 2.72Å" /> | ||
'''F Factor TraI Relaxase Domain bound to F oriT Single-stranded DNA'''<br /> | '''F Factor TraI Relaxase Domain bound to F oriT Single-stranded DNA'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The TraI protein of conjugative plasmid F factor binds and cleaves a | + | The TraI protein of conjugative plasmid F factor binds and cleaves a single-stranded region of the plasmid prior to transfer to a recipient. TraI36, an N-terminal TraI fragment, binds ssDNA with a subnanomolar K(D) and remarkable sequence specificity. The structure of the TraI36 Y16F variant bound to ssDNA reveals specificity determinants, including a ssDNA intramolecular 3 base interaction and two pockets within the protein's binding cleft that accommodate bases in a knob-into-hole fashion. Mutagenesis results underscore the intricate design of the binding site, with the greatest effects resulting from substitutions for residues that both contact ssDNA and stabilize protein structure. The active site architecture suggests that the bound divalent cation, which is essential for catalysis, both positions the DNA by liganding two oxygens of the scissile phosphate and increases the partial positive charge on the phosphorus to enhance nucleophilic attack. |
==About this Structure== | ==About this Structure== | ||
| - | 2A0I 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 MG and IMD as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http:// | + | 2A0I 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=IMD:'>IMD</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2A0I OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Escherichia coli]] | [[Category: Escherichia coli]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Anderson, B | + | [[Category: Anderson, B J.]] |
[[Category: Datta, S.]] | [[Category: Datta, S.]] | ||
[[Category: Ebie, A.]] | [[Category: Ebie, A.]] | ||
[[Category: Hargreaves, V.]] | [[Category: Hargreaves, V.]] | ||
| - | [[Category: Harley, M | + | [[Category: Harley, M J.]] |
[[Category: Larkin, C.]] | [[Category: Larkin, C.]] | ||
| - | [[Category: Schildbach, J | + | [[Category: Schildbach, J F.]] |
[[Category: IMD]] | [[Category: IMD]] | ||
[[Category: MG]] | [[Category: MG]] | ||
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[[Category: single-stranded dna]] | [[Category: single-stranded dna]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 16:22:25 2008'' |
Revision as of 14:22, 21 February 2008
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F Factor TraI Relaxase Domain bound to F oriT Single-stranded DNA
Overview
The TraI protein of conjugative plasmid F factor binds and cleaves a single-stranded region of the plasmid prior to transfer to a recipient. TraI36, an N-terminal TraI fragment, binds ssDNA with a subnanomolar K(D) and remarkable sequence specificity. The structure of the TraI36 Y16F variant bound to ssDNA reveals specificity determinants, including a ssDNA intramolecular 3 base interaction and two pockets within the protein's binding cleft that accommodate bases in a knob-into-hole fashion. Mutagenesis results underscore the intricate design of the binding site, with the greatest effects resulting from substitutions for residues that both contact ssDNA and stabilize protein structure. The active site architecture suggests that the bound divalent cation, which is essential for catalysis, both positions the DNA by liganding two oxygens of the scissile phosphate and increases the partial positive charge on the phosphorus to enhance nucleophilic attack.
About this Structure
2A0I is a Single protein structure of sequence from Escherichia coli with and as ligands. Full crystallographic information is available from OCA.
Reference
Inter- and intramolecular determinants of the specificity of single-stranded DNA binding and cleavage by the F factor relaxase., Larkin C, Datta S, Harley MJ, Anderson BJ, Ebie A, Hargreaves V, Schildbach JF, Structure. 2005 Oct;13(10):1533-44. PMID:16216584
Page seeded by OCA on Thu Feb 21 16:22:25 2008
