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1wet

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Revision as of 06:23, 4 April 2018

STRUCTURE OF THE PURR-GUANINE-PURF OPERATOR COMPLEX

Structural highlights

1wet is a 2 chain structure with sequence from Escherichia coli. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Ligands:
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

[PURR_ECOLI] Is the main repressor of the genes involved in the de novo synthesis of purine nucleotides, regulating purB, purC, purEK, purF, purHD, purL, purMN and guaBA expression. In addition, it participates in the regulation or coregulation of genes involved in de novo pyrimidine nucleotide biosynthesis, salvage and uptake (pyrC, pyrD, carAB and codBA), and of several genes encoding enzymes necessary for nucleotide and polyamine biosynthesis (prsA, glyA, gcvTHP, speA, glnB). Binds to a 16-bp palindromic sequence located within the promoter region of pur regulon genes. The consensus binding sequence is 5'-ACGCAAACGTTTTCNT-3'. PurR is allosterically activated to bind its cognate DNA by binding the purine corepressors, hypoxanthine or guanine, thereby effecting transcription repression.^[1] ^[2] ^[3] ^[4]

Evolutionary Conservation

Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.

Publication Abstract from PubMed

The purine repressor, PurR, is the master regulatory protein of de novo purine nucleotide biosynthesis in Escherichia coli. This dimeric transcription factor is activated to bind to cognate DNA operator sites by initially binding either of its physiologically relevant, high affinity corepressors, hypoxanthine (Kd = 9.3 microM) or guanine (Kd = 1.5 microM). Here, we report the 2.5-A crystal structure of the PurR-guanine-purF operator ternary complex and complete the atomic description of 6-oxopurine-induced repression by PurR. As anticipated, the structure of the PurR-guanine-purF operator complex is isomorphous to the PurR-hypoxanthine-purF operator complex, and their protein-DNA and protein-corepressor interactions are nearly identical. The former finding confirms the use of an identical allosteric DNA-binding mechanism whereby corepressor binding 40 A from the DNA-binding domain juxtaposes the hinge regions of each monomer, thus favoring the formation and insertion of the critical minor groove-binding hinge helices. Strikingly, the higher binding affinity of guanine for PurR and the ability of PurR to discriminate against 2-oxopurines do not result from direct protein-ligand interactions, but rather from a water-mediated contact with the exocyclic N-2 of guanine, which dictates the presence of a donor group on the corepressor, and the better electrostatic complementarity of the guanine base and the corepressor-binding pocket.

The X-ray structure of the PurR-guanine-purF operator complex reveals the contributions of complementary electrostatic surfaces and a water-mediated hydrogen bond to corepressor specificity and binding affinity.,Schumacher MA, Glasfeld A, Zalkin H, Brennan RG J Biol Chem. 1997 Sep 5;272(36):22648-53. PMID:9278422^[5]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

References

↑ Meng LM, Kilstrup M, Nygaard P. Autoregulation of PurR repressor synthesis and involvement of purR in the regulation of purB, purC, purL, purMN and guaBA expression in Escherichia coli. Eur J Biochem. 1990 Jan 26;187(2):373-9. PMID:2404765
↑ Rolfes RJ, Zalkin H. Purification of the Escherichia coli purine regulon repressor and identification of corepressors. J Bacteriol. 1990 Oct;172(10):5637-42. PMID:2211500
↑ Choi KY, Zalkin H. Structural characterization and corepressor binding of the Escherichia coli purine repressor. J Bacteriol. 1992 Oct;174(19):6207-14. PMID:1400170
↑ Devroede N, Thia-Toong TL, Gigot D, Maes D, Charlier D. Purine and pyrimidine-specific repression of the Escherichia coli carAB operon are functionally and structurally coupled. J Mol Biol. 2004 Feb 6;336(1):25-42. PMID:14741201
↑ Schumacher MA, Glasfeld A, Zalkin H, Brennan RG. The X-ray structure of the PurR-guanine-purF operator complex reveals the contributions of complementary electrostatic surfaces and a water-mediated hydrogen bond to corepressor specificity and binding affinity. J Biol Chem. 1997 Sep 5;272(36):22648-53. PMID:9278422

1 Structural highlights
2 Function
3 Evolutionary Conservation
4 Publication Abstract from PubMed
5 See Also
6 References

Proteopedia Page Contributors and Editors (what is this?)

OCA

Retrieved from "http://52.214.119.220/wiki/index.php/1wet"

@@ Line 1: / Line 1: @@
 ==STRUCTURE OF THE PURR-GUANINE-PURF OPERATOR COMPLEX==
 <StructureSection load='1wet' size='340' side='right' caption='[[1wet]], [[Resolution|resolution]] 2.60&Aring;' scene=''>
@@ Line 4: / Line 5: @@
 <table><tr><td colspan='2'>[[1wet]] is a 2 chain structure with sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1WET OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1WET FirstGlance]. <br>
 </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=GUN:GUANINE'>GUN</scene></td></tr>
-<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1wet FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1wet OCA], [http://pdbe.org/1wet PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=1wet RCSB], [http://www.ebi.ac.uk/pdbsum/1wet PDBsum]</span></td></tr>
+<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1wet FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1wet OCA], [http://pdbe.org/1wet PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=1wet RCSB], [http://www.ebi.ac.uk/pdbsum/1wet PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=1wet ProSAT]</span></td></tr>
 </table>
 == Function ==
@@ Line 12: / Line 13: @@
 Check<jmol>
   <jmolCheckbox>
-    <scriptWhenChecked>select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/we/1wet_consurf.spt"</scriptWhenChecked>
+    <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/we/1wet_consurf.spt"</scriptWhenChecked>
     <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked>
     <text>to colour the structure by Evolutionary Conservation</text>
   </jmolCheckbox>
-</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/chain_selection.php?pdb_ID=2ata ConSurf].
+</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=1wet ConSurf].
 <div style="clear:both"></div>
 <div style="background-color:#fffaf0;">

1wet

From Proteopedia

Revision as of 06:23, 4 April 2018

STRUCTURE OF THE PURR-GUANINE-PURF OPERATOR COMPLEX

Structural highlights

Function

Evolutionary Conservation

Publication Abstract from PubMed

See Also

References

Contents

Proteopedia Page Contributors and Editors (what is this?)

Views

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