1xrx
From Proteopedia
(New page: 200px<br /><applet load="1xrx" size="450" color="white" frame="true" align="right" spinBox="true" caption="1xrx, resolution 2.15Å" /> '''Crystal structure of...) |
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| - | [[Image:1xrx.gif|left|200px]]<br /><applet load="1xrx" size=" | + | [[Image:1xrx.gif|left|200px]]<br /><applet load="1xrx" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1xrx, resolution 2.15Å" /> | caption="1xrx, resolution 2.15Å" /> | ||
'''Crystal structure of a DNA-binding protein'''<br /> | '''Crystal structure of a DNA-binding protein'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Escherichia coli SeqA binds clusters of transiently hemimethylated GATC | + | Escherichia coli SeqA binds clusters of transiently hemimethylated GATC sequences and sequesters the origin of replication, oriC, from methylation and premature reinitiation. Besides oriC, SeqA binds and organizes newly synthesized DNA at replication forks. Binding to multiple GATC sites is crucial for the formation of stable SeqA-DNA complexes. Here we report the crystal structure of the oligomerization domain of SeqA (SeqA-N). The structural unit of SeqA-N is a dimer, which oligomerizes to form a filament. Mutations that disrupt filament formation lead to asynchronous DNA replication, but the resulting SeqA dimer can still bind two GATC sites separated from 5 to 34 base pairs. Truncation of the linker between the oligomerization and DNA-binding domains restricts SeqA to bind two GATC sites separated by one or two full turns. We propose a model of a SeqA filament interacting with multiple GATC sites that accounts for both origin sequestration and chromosome organization. |
==About this Structure== | ==About this Structure== | ||
| - | 1XRX 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 CA as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http:// | + | 1XRX 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=CA:'>CA</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1XRX OCA]. |
==Reference== | ==Reference== | ||
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[[Category: protein filament]] | [[Category: protein filament]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 15:58:04 2008'' |
Revision as of 13:58, 21 February 2008
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Crystal structure of a DNA-binding protein
Overview
Escherichia coli SeqA binds clusters of transiently hemimethylated GATC sequences and sequesters the origin of replication, oriC, from methylation and premature reinitiation. Besides oriC, SeqA binds and organizes newly synthesized DNA at replication forks. Binding to multiple GATC sites is crucial for the formation of stable SeqA-DNA complexes. Here we report the crystal structure of the oligomerization domain of SeqA (SeqA-N). The structural unit of SeqA-N is a dimer, which oligomerizes to form a filament. Mutations that disrupt filament formation lead to asynchronous DNA replication, but the resulting SeqA dimer can still bind two GATC sites separated from 5 to 34 base pairs. Truncation of the linker between the oligomerization and DNA-binding domains restricts SeqA to bind two GATC sites separated by one or two full turns. We propose a model of a SeqA filament interacting with multiple GATC sites that accounts for both origin sequestration and chromosome organization.
About this Structure
1XRX is a Single protein structure of sequence from Escherichia coli with as ligand. Full crystallographic information is available from OCA.
Reference
Crystal structure of a SeqA-N filament: implications for DNA replication and chromosome organization., Guarne A, Brendler T, Zhao Q, Ghirlando R, Austin S, Yang W, EMBO J. 2005 Apr 20;24(8):1502-11. Epub 2005 Mar 31. PMID:15933720
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