2qg9

<table><tr><td colspan='2'>[[2qg9]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/"bacillus_coli"_migula_1895 "bacillus coli" migula 1895]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2QG9 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2QG9 FirstGlance]. <br>

</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=ZN:ZINC+ION'>ZN</scene></td></tr>

<tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat"><div style='overflow: auto; max-height: 3em;'>[[1nbe|1nbe]], [[1rah|1rah]], [[6at1|6at1]], [[2qgf|2qgf]]</div></td></tr>

<tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">pyrB ([https://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=562 "Bacillus coli" Migula 1895]), pyrI ([https://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=562 "Bacillus coli" Migula 1895])</td></tr>

<tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[https://en.wikipedia.org/wiki/Aspartate_carbamoyltransferase Aspartate carbamoyltransferase], with EC number [https://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.1.3.2 2.1.3.2] </span></td></tr>

[[https://www.uniprot.org/uniprot/PYRI_ECOLI PYRI_ECOLI]] Involved in allosteric regulation of aspartate carbamoyltransferase.[HAMAP-Rule:MF_00002]

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== Publication Abstract from PubMed ==

Asp19 and His20 of Escherichia coli aspartate transcarbamoylase (EC 2.1.3.2) function in the binding of the triphosphate and ribose moieties of ATP and CTP and thereby may mediate important heterotropic regulation. The roles of these residues were investigated by individually mutating each of them to alanine and determining both the kinetic parameters and the structures of the mutant enzymes. The structures were determined by X-ray crystallography at 2.15 and 2.75 A resolution for His20Ar and Asp19Ar, respectively. Analysis was carried out on the unliganded T-state form. The structures of the mutants did not show gross structural divergence from the canonical T-state, but showed small and systematic differences that were analyzed by global conformational analysis. Structural analysis and comparison with other regulatory-chain mutants confirmed that the Asp19Ar mutant represents the stabilized T-state, while structural analysis of the His20Ar form indicated that it represents an equilibrium shifted towards the R-state. Global analysis of the Asp19Ar and His20Ar enzymes suggested a possible role as molecular modulators of the heterotropic effects caused by the binding of nucleotides at the regulatory site. These studies highlighted the structural determinants of T- or R-state stabilization. Additionally, application of the ;consensus modeling' methodology combined with high-resolution data allowed the determination of unclear structural features contributing to nucleotide specificity and the role of the N-termini of the regulatory chains.

Comparison of two T-state structures of regulatory-chain mutants of Escherichia coli aspartate transcarbamoylase suggests that His20 and Asp19 modulate the response to heterotropic effectors.,Stec B, Williams MK, Stieglitz KA, Kantrowitz ER Acta Crystallogr D Biol Crystallogr. 2007 Dec;63(Pt 12):1243-53. Epub 2007, Nov 16. PMID:18084072<ref>PMID:18084072</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 2qg9" style="background-color:#fffaf0;"></div>

== References ==

<references/>

[[Category: Bacillus coli migula 1895]]

[[Category: Aspartate carbamoyltransferase]]

[[Category: Kantrowitz, E R]]

[[Category: Stec, B]]

[[Category: Stieglitz, K A]]

[[Category: Williams, M K]]

[[Category: Transferase-transferase regulator complex]]