2h8c
From Proteopedia
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==Overview== | ==Overview== | ||
| - | We have determined the structure of a catalytically inactive D70N variant | + | We have determined the structure of a catalytically inactive D70N variant of the Escherichia coli RusA resolvase bound to a duplex DNA substrate that reveals critical protein-DNA interactions and permits a much clearer understanding of the interaction of the enzyme with a Holliday junction (HJ). The RusA enzyme cleaves HJs, the fourway DNA branchpoints formed by homologous recombination, by introducing symmetrical cuts in the phosphodiester backbone in a Mg2+ dependent reaction. Although, RusA shows a high level of selectivity for DNA junctions, preferring to bind fourway junctions over other substrates in vitro, it has also been shown to have appreciable affinity for duplex DNA. However, RusA does not show DNA cleavage activity with duplex substrates. Our structure suggests the possible basis for structural selectivity as well as sources of the sequence specificity observed for DNA cleavage by RusA. |
==About this Structure== | ==About this Structure== | ||
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[[Category: Escherichia coli]] | [[Category: Escherichia coli]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Macmaster, R | + | [[Category: Macmaster, R A.]] |
[[Category: protein-dna complex]] | [[Category: protein-dna complex]] | ||
[[Category: recombination]] | [[Category: recombination]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 17:39:16 2008'' |
Revision as of 15:39, 21 February 2008
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Structure of RusA D70N in complex with DNA
Overview
We have determined the structure of a catalytically inactive D70N variant of the Escherichia coli RusA resolvase bound to a duplex DNA substrate that reveals critical protein-DNA interactions and permits a much clearer understanding of the interaction of the enzyme with a Holliday junction (HJ). The RusA enzyme cleaves HJs, the fourway DNA branchpoints formed by homologous recombination, by introducing symmetrical cuts in the phosphodiester backbone in a Mg2+ dependent reaction. Although, RusA shows a high level of selectivity for DNA junctions, preferring to bind fourway junctions over other substrates in vitro, it has also been shown to have appreciable affinity for duplex DNA. However, RusA does not show DNA cleavage activity with duplex substrates. Our structure suggests the possible basis for structural selectivity as well as sources of the sequence specificity observed for DNA cleavage by RusA.
About this Structure
2H8C is a Single protein structure of sequence from Escherichia coli. Full crystallographic information is available from OCA.
Reference
RusA Holliday junction resolvase: DNA complex structure--insights into selectivity and specificity., Macmaster R, Sedelnikova S, Baker PJ, Bolt EL, Lloyd RG, Rafferty JB, Nucleic Acids Res. 2006;34(19):5577-84. Epub 2006 Oct 5. PMID:17028102
Page seeded by OCA on Thu Feb 21 17:39:16 2008
