1a3c

<StructureSection load='1a3c' size='340' side='right' caption='[[1a3c]], [[Resolution|resolution]] 1.60&Aring;' scene=''>

<table><tr><td colspan='2'>[[1a3c]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/"vibrio_subtilis"_ehrenberg_1835 "vibrio subtilis" ehrenberg 1835]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1A3C OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1A3C FirstGlance]. <br>

</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=SM:SAMARIUM+(III)+ION'>SM</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene></td></tr>

<tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">PYRR ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=1423 "Vibrio subtilis" Ehrenberg 1835])</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=1a3c FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1a3c OCA], [http://pdbe.org/1a3c PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=1a3c RCSB], [http://www.ebi.ac.uk/pdbsum/1a3c PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=1a3c ProSAT]</span></td></tr>

[[http://www.uniprot.org/uniprot/PYRR_BACSU PYRR_BACSU]] Regulates transcriptional attenuation of the pyrimidine nucleotide (pyr) operon by binding in a uridine-dependent manner to specific sites on pyr mRNA. This disrupts an antiterminator hairpin in the RNA and favors formation of a downstream transcription terminator, leading to a reduced expression of downstream genes.[HAMAP-Rule:MF_01219] Also displays a weak uracil phosphoribosyltransferase activity which is not physiologically significant.[HAMAP-Rule:MF_01219]

<scriptWhenChecked>select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/a3/1a3c_consurf.spt"</scriptWhenChecked>

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== Publication Abstract from PubMed ==

BACKGROUND: The expression of pyrimidine nucleotide biosynthetic (pyr) genes in Bacillus subtilis is regulated by transcriptional attenuation. The PyrR attenuation protein binds to specific sites in pyr mRNA, allowing the formation of downstream terminator structures. UMP and 5-phosphoribosyl-1-pyrophosphate (PRPP), a nucleotide metabolite, are co-regulators with PyrR. The smallest RNA shown to bind tightly to PyrR is a 28-30 nucleotide stem-loop that contains a purine-rich bulge and a putative-GNRA tetraloop. PyrR is also a uracil phosphoribosyltransferase (UPRTase), although the relationship between enzymatic activity and RNA recognition is unclear, and the UPRTase activity of PyrR is not physiologically significant in B. subtilis. Elucidating the role of PyrR structural motifs in UMP-dependent RNA binding is an important step towards understanding the mechanism of pyr transcriptional attenuation. RESULTS: The 1.6 A crystal structure of B. subtilis PyrR has been determined by multiwavelength anomalous diffraction, using a Sm co-crystal. As expected, the structure of PyrR is homologous to those proteins of the large type I PRTase structural family; it is most similar to hypoxanthine-guanine-xanthine PRTase (HGXPRTase). The PyrR dimer differs from other PRTase dimers, suggesting it may have evolved specifically for RNA binding. A large, basic, surface at the dimer interface is an obvious RNA-binding site and uracil specificity is probably provided by hydrogen bonds from mainchain and sidechain atoms in the hood subdomain. These models of RNA and UMP binding are consistent with biological data. CONCLUSIONS: The B. subtilis protein PyrR has adapted the substrate- and product-binding capacities of a PRTase, probably an HGXPRTase, producing a new regulatory function in which the substrate and product are co-regulators of transcription termination. The structure is consistent with the idea that PyrR regulatory function is independent of catalytic activity, which is likely to be extremely low under physiological conditions.

Adaptation of an enzyme to regulatory function: structure of Bacillus subtilis PyrR, a pyr RNA-binding attenuation protein and uracil phosphoribosyltransferase.,Tomchick DR, Turner RJ, Switzer RL, Smith JL Structure. 1998 Mar 15;6(3):337-50. PMID:9551555<ref>PMID:9551555</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>

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<div class="pdbe-citations 1a3c" style="background-color:#fffaf0;"></div>

== References ==

<references/>

[[Category: Vibrio subtilis ehrenberg 1835]]

[[Category: Smith, J L]]

[[Category: Switzer, R W]]

[[Category: Tomchick, D R]]

[[Category: Turner, R J]]

[[Category: Attenuation protein]]

[[Category: Transferase]]