1nlf: Difference between revisions

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Crystal Structure of DNA Helicase RepA in complex with sulfate at 1.95 A resolution

OverviewOverview

The structure of a new crystal form (space group C2), grown at pH 8.0 and diffracting to 1.95 A resolution, of the replicative homo-hexameric DNA helicase RepA encoded by plasmid RSF1010 is reported. In contrast to previous crystals grown at pH 6.0 in space group P2(1) (Niedenzu et al., 2001), only one half (a trimer) of the RepA hexamer occupies the asymmetric unit of the space-group C2 crystals. The new crystal packing explains the pH-dependent hexamer-hexamer association mechanism of RepA. The C-terminus (264)VLERQRKSKGVPRGEA(279), which could not be modelled in the previous structure, is clearly defined in the present electron density except for the last four amino acids. Sulfate anions occupy the six ATPase active sites of RepA at positions where the product phosphates are supposed to bind. Binding of sulfate anions induces conformational changes both at the ATPase active sites and throughout the whole molecular structure. In agreement with electron microscopy, the above studies implicate structural changes to an "open" form that may occur upon binding and hydrolysis of nucleotide 5'-triphosphates and could be essential for DNA duplex-unwinding activity.

About this StructureAbout this Structure

1NLF is a Single protein structure of sequence from Escherichia coli with as ligand. Full crystallographic information is available from OCA.

ReferenceReference

Structure of DNA helicase RepA in complex with sulfate at 1.95 A resolution implicates structural changes to an "open" form., Xu H, Strater N, Schroder W, Bottcher C, Ludwig K, Saenger W, Acta Crystallogr D Biol Crystallogr. 2003 May;59(Pt 5):815-22. Epub 2003, Apr 25. PMID:12777796

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OCA

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-[[Image:1nlf.jpg|left|200px]]<br /><applet load="1nlf" size="450" color="white" frame="true" align="right" spinBox="true"
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 caption="1nlf, resolution 1.95&Aring;" />
 '''Crystal Structure of DNA Helicase RepA in complex with sulfate at 1.95 A resolution'''<br />
 ==Overview==
-The structure of a new crystal form (space group C2), grown at pH 8.0 and, diffracting to 1.95 A resolution, of the replicative homo-hexameric DNA, helicase RepA encoded by plasmid RSF1010 is reported. In contrast to, previous crystals grown at pH 6.0 in space group P2(1) (Niedenzu et al., 2001), only one half (a trimer) of the RepA hexamer occupies the, asymmetric unit of the space-group C2 crystals. The new crystal packing, explains the pH-dependent hexamer-hexamer association mechanism of RepA., The C-terminus (264)VLERQRKSKGVPRGEA(279), which could not be modelled in, the previous structure, is clearly defined in the present electron density, except for the last four amino acids. Sulfate anions occupy the six ATPase, active sites of RepA at positions where the product phosphates are, supposed to bind. Binding of sulfate anions induces conformational changes, both at the ATPase active sites and throughout the whole molecular, structure. In agreement with electron microscopy, the above studies, implicate structural changes to an "open" form that may occur upon binding, and hydrolysis of nucleotide 5'-triphosphates and could be essential for, DNA duplex-unwinding activity.
+The structure of a new crystal form (space group C2), grown at pH 8.0 and diffracting to 1.95 A resolution, of the replicative homo-hexameric DNA helicase RepA encoded by plasmid RSF1010 is reported. In contrast to previous crystals grown at pH 6.0 in space group P2(1) (Niedenzu et al., 2001), only one half (a trimer) of the RepA hexamer occupies the asymmetric unit of the space-group C2 crystals. The new crystal packing explains the pH-dependent hexamer-hexamer association mechanism of RepA. The C-terminus (264)VLERQRKSKGVPRGEA(279), which could not be modelled in the previous structure, is clearly defined in the present electron density except for the last four amino acids. Sulfate anions occupy the six ATPase active sites of RepA at positions where the product phosphates are supposed to bind. Binding of sulfate anions induces conformational changes both at the ATPase active sites and throughout the whole molecular structure. In agreement with electron microscopy, the above studies implicate structural changes to an "open" form that may occur upon binding and hydrolysis of nucleotide 5'-triphosphates and could be essential for DNA duplex-unwinding activity.
 ==About this Structure==
-NLF 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 SO4 as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1NLF OCA].
+NLF 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=SO4:'>SO4</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1NLF OCA].
 ==Reference==
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 [[Category: replicative dna helicase structural changes]]
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+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:07:19 2008''