View source for 1o57


==CRYSTAL STRUCTURE OF THE PURINE OPERON REPRESSOR OF BACILLUS SUBTILIS==
<StructureSection load='1o57' size='340' side='right'caption='[[1o57]], [[Resolution|resolution]] 2.20&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1o57]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Bacillus_subtilis Bacillus subtilis]. This structure supersedes the now removed PDB entry [http://oca.weizmann.ac.il/oca-bin/send-pdb?obs=1&id=1p41 1p41]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1O57 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1O57 FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2.2&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=1PE:PENTAETHYLENE+GLYCOL'>1PE</scene>, <scene name='pdbligand=2PE:NONAETHYLENE+GLYCOL'>2PE</scene>, <scene name='pdbligand=EPE:4-(2-HYDROXYETHYL)-1-PIPERAZINE+ETHANESULFONIC+ACID'>EPE</scene>, <scene name='pdbligand=P6G:HEXAETHYLENE+GLYCOL'>P6G</scene>, <scene name='pdbligand=PG4:TETRAETHYLENE+GLYCOL'>PG4</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene></td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=1o57 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1o57 OCA], [https://pdbe.org/1o57 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1o57 RCSB], [https://www.ebi.ac.uk/pdbsum/1o57 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1o57 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/PURR_BACSU PURR_BACSU] Controls the transcription of the pur operon for purine biosynthetic genes, binds to the control region of the operon. DNA binding is inhibited by 5-phosphoribosyl 1-pyrophosphate.
== Evolutionary Conservation ==
[[Image:Consurf_key_small.gif|200px|right]]
Check<jmol>
  <jmolCheckbox>
    <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/o5/1o57_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/main_output.php?pdb_ID=1o57 ConSurf].
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== Publication Abstract from PubMed ==
The purine repressor from Bacillus subtilis, PurR, represses transcription from a number of genes with functions in the synthesis, transport, and metabolism of purines. The 2.2-A crystal structure of PurR reveals a two-domain protein organized as a dimer. The larger C-terminal domain belongs to the PRT structural family, in accord with a sequence motif for binding the inducer phosphoribosylpyrophosphate (PRPP). The PRT domain is fused to a smaller N-terminal domain that belongs to the winged-helix family of DNA binding proteins. A positively charged surface on the winged-helix domain likely binds specific DNA sequences in the recognition site. A second positively charged surface surrounds the PRPP site at the opposite end of the PurR dimer. Conserved amino acids in the sequences of PurR homologs in 21 gram-positive bacteria cluster on the proposed recognition surface of the winged-helix domain and around the PRPP binding site at the opposite end of the molecule, supporting a common function of DNA and PRPP binding for all of the proteins. The structure supports a binding mechanism in which extended regions of DNA interact with extensive protein surface. Unlike most PRT proteins, which are phosphoribosyltransferases (PRTases), PurR lacks catalytic activity. This is explained by a tyrosine side chain that blocks the site for a nucleophile cosubstrate in PRTases. Thus, B. subtilis has adapted an enzyme fold to serve as an effector-binding domain and has used it in a novel combination with the DNA-binding winged-helix domain as a repressor of purine genes.

The purine repressor of Bacillus subtilis: a novel combination of domains adapted for transcription regulation.,Sinha SC, Krahn J, Shin BS, Tomchick DR, Zalkin H, Smith JL J Bacteriol. 2003 Jul;185(14):4087-98. PMID:12837783<ref>PMID:12837783</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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==See Also==
*[[Purine repressor|Purine repressor]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Bacillus subtilis]]
[[Category: Large Structures]]
[[Category: Krahn J]]
[[Category: Shin BS]]
[[Category: Sinha SC]]
[[Category: Smith JL]]
[[Category: Tomchick DR]]
[[Category: Zalkin H]]