2q2k: Difference between revisions
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==Overview== | ==Overview== | ||
The stable inheritance of genetic material depends on accurate DNA | The stable inheritance of genetic material depends on accurate DNA partition. Plasmids serve as tractable model systems to study DNA segregation because they require only a DNA centromere, a centromere-binding protein and a force-generating ATPase. The centromeres of partition (par) systems typically consist of a tandem arrangement of direct repeats. The best-characterized par system contains a centromere-binding protein called ParR and an ATPase called ParM. In the first step of segregation, multiple ParR proteins interact with the centromere repeats to form a large nucleoprotein complex of unknown structure called the segrosome, which binds ParM filaments. pSK41 ParR binds a centromere consisting of multiple 20-base-pair (bp) tandem repeats to mediate both transcription autoregulation and segregation. Here we report the structure of the pSK41 segrosome revealed in the crystal structure of a ParR-DNA complex. In the crystals, the 20-mer tandem repeats stack pseudo-continuously to generate the full-length centromere with the ribbon-helix-helix (RHH) fold of ParR binding successive DNA repeats as dimer-of-dimers. Remarkably, the dimer-of-dimers assemble in a continuous protein super-helical array, wrapping the DNA about its positive convex surface to form a large segrosome with an open, solenoid-shaped structure, suggesting a mechanism for ParM capture and subsequent plasmid segregation. | ||
==About this Structure== | ==About this Structure== | ||
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[[Category: Firth, N.]] | [[Category: Firth, N.]] | ||
[[Category: Glover, T.]] | [[Category: Glover, T.]] | ||
[[Category: Schumacher, M | [[Category: Schumacher, M A.]] | ||
[[Category: EPE]] | [[Category: EPE]] | ||
[[Category: dna binding protein/dna complex]] | [[Category: dna binding protein/dna complex]] | ||
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[[Category: segregation]] | [[Category: segregation]] | ||
''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 18:35:29 2008'' | ||
Revision as of 16:35, 21 February 2008
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Structure of nucleic-acid binding protein
Overview
The stable inheritance of genetic material depends on accurate DNA partition. Plasmids serve as tractable model systems to study DNA segregation because they require only a DNA centromere, a centromere-binding protein and a force-generating ATPase. The centromeres of partition (par) systems typically consist of a tandem arrangement of direct repeats. The best-characterized par system contains a centromere-binding protein called ParR and an ATPase called ParM. In the first step of segregation, multiple ParR proteins interact with the centromere repeats to form a large nucleoprotein complex of unknown structure called the segrosome, which binds ParM filaments. pSK41 ParR binds a centromere consisting of multiple 20-base-pair (bp) tandem repeats to mediate both transcription autoregulation and segregation. Here we report the structure of the pSK41 segrosome revealed in the crystal structure of a ParR-DNA complex. In the crystals, the 20-mer tandem repeats stack pseudo-continuously to generate the full-length centromere with the ribbon-helix-helix (RHH) fold of ParR binding successive DNA repeats as dimer-of-dimers. Remarkably, the dimer-of-dimers assemble in a continuous protein super-helical array, wrapping the DNA about its positive convex surface to form a large segrosome with an open, solenoid-shaped structure, suggesting a mechanism for ParM capture and subsequent plasmid segregation.
About this Structure
2Q2K is a Single protein structure of sequence from Staphylococcus aureus with EPE as ligand. Full crystallographic information is available from OCA.
Reference
Segrosome structure revealed by a complex of ParR with centromere DNA., Schumacher MA, Glover TC, Brzoska AJ, Jensen SO, Dunham TD, Skurray RA, Firth N, Nature. 2007 Dec 20;450(7173):1268-71. PMID:18097417
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