1hwt
From Proteopedia
(New page: 200px<br /><applet load="1hwt" size="450" color="white" frame="true" align="right" spinBox="true" caption="1hwt, resolution 2.5Å" /> '''STRUCTURE OF A HAP1/D...) |
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| - | [[Image:1hwt.gif|left|200px]]<br /><applet load="1hwt" size=" | + | [[Image:1hwt.gif|left|200px]]<br /><applet load="1hwt" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1hwt, resolution 2.5Å" /> | caption="1hwt, resolution 2.5Å" /> | ||
'''STRUCTURE OF A HAP1/DNA COMPLEX REVEALS DRAMATICALLY ASYMMETRIC DNA BINDING BY A HOMODIMERIC PROTEIN'''<br /> | '''STRUCTURE OF A HAP1/DNA COMPLEX REVEALS DRAMATICALLY ASYMMETRIC DNA BINDING BY A HOMODIMERIC PROTEIN'''<br /> | ||
==Overview== | ==Overview== | ||
| - | HAP1 is a member of a family of fungal transcription factors that contain | + | HAP1 is a member of a family of fungal transcription factors that contain a Zn2Cys6 binuclear cluster domain and bind as homodimers to sequences containing two DNA half sites. We have determined the 2.5 A crystal structure of HAP1 bound to a cognate upstream activation sequence from the CYC7 gene. The structure reveals that HAP1 is bound in a dramatically asymmetric manner to the DNA target. This asymmetry aligns the Zn2Cys6 domains in a tandem head-to-tail fashion to contact two DNA half sites, positions an N-terminal arm of one of the protein subunits to interact with the inter-half site base pairs in the DNA minor groove, and suggests a mechanism by which DNA-binding facilitates asymmetric dimerization by HAP1. Comparisons with the DNA complexes of the related GAL4, PPR1 and PUT3 proteins illustrate how a conserved protein domain can be reoriented to recognize DNA half sites of different polarities and how homodimeric proteins adopt dramatically asymmetric structures to recognize cognate DNA targets. |
==About this Structure== | ==About this Structure== | ||
| - | 1HWT is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Saccharomyces_cerevisiae Saccharomyces cerevisiae] with ZN as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http:// | + | 1HWT is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Saccharomyces_cerevisiae Saccharomyces cerevisiae] with <scene name='pdbligand=ZN:'>ZN</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1HWT OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Guarente, L.]] | [[Category: Guarente, L.]] | ||
| - | [[Category: King, D | + | [[Category: King, D A.]] |
[[Category: Marmorstein, R.]] | [[Category: Marmorstein, R.]] | ||
[[Category: Zhang, L.]] | [[Category: Zhang, L.]] | ||
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[[Category: transcription factor]] | [[Category: transcription factor]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:05:36 2008'' |
Revision as of 11:05, 21 February 2008
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STRUCTURE OF A HAP1/DNA COMPLEX REVEALS DRAMATICALLY ASYMMETRIC DNA BINDING BY A HOMODIMERIC PROTEIN
Overview
HAP1 is a member of a family of fungal transcription factors that contain a Zn2Cys6 binuclear cluster domain and bind as homodimers to sequences containing two DNA half sites. We have determined the 2.5 A crystal structure of HAP1 bound to a cognate upstream activation sequence from the CYC7 gene. The structure reveals that HAP1 is bound in a dramatically asymmetric manner to the DNA target. This asymmetry aligns the Zn2Cys6 domains in a tandem head-to-tail fashion to contact two DNA half sites, positions an N-terminal arm of one of the protein subunits to interact with the inter-half site base pairs in the DNA minor groove, and suggests a mechanism by which DNA-binding facilitates asymmetric dimerization by HAP1. Comparisons with the DNA complexes of the related GAL4, PPR1 and PUT3 proteins illustrate how a conserved protein domain can be reoriented to recognize DNA half sites of different polarities and how homodimeric proteins adopt dramatically asymmetric structures to recognize cognate DNA targets.
About this Structure
1HWT is a Single protein structure of sequence from Saccharomyces cerevisiae with as ligand. Full crystallographic information is available from OCA.
Reference
Structure of a HAP1-DNA complex reveals dramatically asymmetric DNA binding by a homodimeric protein., King DA, Zhang L, Guarente L, Marmorstein R, Nat Struct Biol. 1999 Jan;6(1):64-71. PMID:9886294
Page seeded by OCA on Thu Feb 21 13:05:36 2008
