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1qp9
From Proteopedia
(New page: 200px<br /><applet load="1qp9" size="450" color="white" frame="true" align="right" spinBox="true" caption="1qp9, resolution 2.8Å" /> '''STRUCTURE OF HAP1-PC7...) |
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| - | [[Image:1qp9.gif|left|200px]]<br /><applet load="1qp9" size=" | + | [[Image:1qp9.gif|left|200px]]<br /><applet load="1qp9" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1qp9, resolution 2.8Å" /> | caption="1qp9, resolution 2.8Å" /> | ||
'''STRUCTURE OF HAP1-PC7 COMPLEXED TO THE UAS OF CYC7'''<br /> | '''STRUCTURE OF HAP1-PC7 COMPLEXED TO THE UAS OF CYC7'''<br /> | ||
==Overview== | ==Overview== | ||
| - | HAP1 is a transcription factor in yeast whose DNA-binding domain has been | + | HAP1 is a transcription factor in yeast whose DNA-binding domain has been implicated in directly affecting transcriptional activation. Two separate mutations in the DNA-binding domain, S63G (HAP1-PC7) and S63R (HAP1-18), retain wild-type binding affinity. However, HAP1-PC7 is transcriptionally silent while HAP1-18 shows highly elevated levels of transcription. We have determined the X-ray crystal structure of the DNA-binding domain of HAP1-PC7 bound to its DNA target, UAS(CYC7), and compared it to the previously solved HAP1-wt and HAP1-18 complexes to UAS(CYC7). Additionally, we have quantitatively compared the DNA-binding affinity and specificity of the HAP1-PC7, HAP1-18 and HAP1-wt DNA-binding domains. We show that, although the DNA-binding domains of these three proteins bind UAS(CYC7) with comparable affinity and specificity, the protein-DNA interactions are dramatically different between the three complexes. Conserved protein-DNA interactions are largely restricted to an internal DNA sequence that excludes one of the two conserved DNA half-sites of UAS(CYC7) suggesting a mode of recognition distinct from other HAP1 family members. Alternative protein-DNA interactions result in divergent DNA configurations between the three complexes. These results suggest that the differential transcriptional activities of the HAP1, HAP1-18 and HAP1-PC7 proteins are due, at least in part, to alternative protein-DNA contacts, and implies that HAP1-DNA interactions have direct allosteric effects on transcriptional activation. |
==About this Structure== | ==About this Structure== | ||
| - | 1QP9 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:// | + | 1QP9 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=1QP9 OCA]. |
==Reference== | ==Reference== | ||
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[[Category: zinc binuclear cluster]] | [[Category: zinc binuclear cluster]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:42:16 2008'' |
Revision as of 12:42, 21 February 2008
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STRUCTURE OF HAP1-PC7 COMPLEXED TO THE UAS OF CYC7
Overview
HAP1 is a transcription factor in yeast whose DNA-binding domain has been implicated in directly affecting transcriptional activation. Two separate mutations in the DNA-binding domain, S63G (HAP1-PC7) and S63R (HAP1-18), retain wild-type binding affinity. However, HAP1-PC7 is transcriptionally silent while HAP1-18 shows highly elevated levels of transcription. We have determined the X-ray crystal structure of the DNA-binding domain of HAP1-PC7 bound to its DNA target, UAS(CYC7), and compared it to the previously solved HAP1-wt and HAP1-18 complexes to UAS(CYC7). Additionally, we have quantitatively compared the DNA-binding affinity and specificity of the HAP1-PC7, HAP1-18 and HAP1-wt DNA-binding domains. We show that, although the DNA-binding domains of these three proteins bind UAS(CYC7) with comparable affinity and specificity, the protein-DNA interactions are dramatically different between the three complexes. Conserved protein-DNA interactions are largely restricted to an internal DNA sequence that excludes one of the two conserved DNA half-sites of UAS(CYC7) suggesting a mode of recognition distinct from other HAP1 family members. Alternative protein-DNA interactions result in divergent DNA configurations between the three complexes. These results suggest that the differential transcriptional activities of the HAP1, HAP1-18 and HAP1-PC7 proteins are due, at least in part, to alternative protein-DNA contacts, and implies that HAP1-DNA interactions have direct allosteric effects on transcriptional activation.
About this Structure
1QP9 is a Single protein structure of sequence from Saccharomyces cerevisiae with as ligand. Full crystallographic information is available from OCA.
Reference
Structure of HAP1-PC7 bound to DNA: implications for DNA recognition and allosteric effects of DNA-binding on transcriptional activation., Lukens AK, King DA, Marmorstein R, Nucleic Acids Res. 2000 Oct 15;28(20):3853-63. PMID:11024163
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