1fb5

</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=NVA:NORVALINE'>NVA</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;'>[[1oth|1oth]]</div></td></tr>

<tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[https://en.wikipedia.org/wiki/Ornithine_carbamoyltransferase Ornithine carbamoyltransferase], with EC number [https://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.1.3.3 2.1.3.3] </span></td></tr>

== Disease ==

[[https://www.uniprot.org/uniprot/OTC_HUMAN OTC_HUMAN]] Defects in OTC are the cause of ornithine carbamoyltransferase deficiency (OTCD) [MIM:[https://omim.org/entry/311250 311250]]. OTCD is an X-linked disorder of the urea cycle which causes a form of hyperammonemia. Mutations with no residual enzyme activity are always expressed in hemizygote males by a very severe neonatal hyperammonemic coma that generally proves to be fatal. Heterozygous females are either asymptomatic or express orotic aciduria spontaneously or after protein intake. The disorder is treatable with supplemental dietary arginine and low protein diet. The arbitrary classification of patients into the 'neonatal' group (clinical hyperammonemia in the first few days of life) and 'late' onset (clinical presentation after the neonatal period) has been used to differentiate severe from mild forms.<ref>PMID:8081373</ref> <ref>PMID:3170748</ref> <ref>PMID:2474822</ref> <ref>PMID:2347583</ref> <ref>PMID:1671317</ref> <ref>PMID:1721894</ref> <ref>PMID:1480464</ref> <ref>PMID:8099056</ref> <ref>PMID:8019569</ref> <ref>PMID:8081398</ref> <ref>PMID:7951259</ref> <ref>PMID:8530002</ref> <ref>PMID:7474905</ref> <ref>PMID:8807340</ref> [:]<ref>PMID:8956038</ref> <ref>PMID:8956045</ref> <ref>PMID:8830175</ref> <ref>PMID:9286441</ref> <ref>PMID:9065786</ref> <ref>PMID:9143919</ref> <ref>PMID:9266388</ref> <ref>PMID:9452024</ref> <ref>PMID:9452049</ref> <ref>PMID:9452065</ref> [:]<ref>PMID:10502831</ref> <ref>PMID:10070627</ref> <ref>PMID:10737985</ref> <ref>PMID:11793483</ref>

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== Publication Abstract from PubMed ==

Ornithine transcarbamoylase from ovine liver has been purified to homogeneity. Like all anabolic OTCs, the ovine enzyme is a trimer, constituted by identical subunits of 34 kDa. Sequence analysis of the 54 N-terminal residues of ovine OTC shows a high degree of homology with the human enzyme. The optimum pH and the Michaelis constants for the catalytic reaction were determined. The ovine enzyme is the most thermostable one among mammals OTCs, its critical temperature being 6 degrees C higher than those measured for the other enzymes. The enzyme has been crystallised and the structure determined at 3.5 A resolution. Crystals belong to the cubic P4(3)32 space group, with a = b = c = 184.7 A and a solvent content of about 80%. There is no evidence of any ligand in the active site cavity, indicating that the crystals contain an unliganded or T state of the enzyme. The unliganded OTCase enzyme adopts a trimeric structure which, in the crystal, presents a three-fold axis coincident with the crystallographic one. The conformation of each monomer in the trimer is quite similar to that of the liganded human protein, with the exception of a few loops, directly interacting with the substrate(s), which are able to induce a rearrangement of the quaternary organisation of the trimer, that accounts for the cooperative behaviour of the enzyme following the binding of the substrates.

Functional and structural characterization of ovine ornithine transcarbamoylase.,De Gregorio A, Battistutta R, Arena N, Panzalorto M, Francescato P, Valentini G, Bruno G, Zanotti G Org Biomol Chem. 2003 Sep 21;1(18):3178-85. PMID:14527149<ref>PMID:14527149</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 1fb5" style="background-color:#fffaf0;"></div>

[[Category: Ornithine carbamoyltransferase]]

[[Category: Battistutta, R]]

[[Category: Bruno, G]]

[[Category: Francescato, P]]

[[Category: Gregorio, A De]]

[[Category: Panzalorto, M]]

[[Category: Zanotti, G]]

[[Category: Transferase]]