1sep

<table><tr><td colspan='2'>[[1sep]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Lk3_transgenic_mice Lk3 transgenic mice]. The August 2015 RCSB PDB [https://pdb.rcsb.org/pdb/static.do?p=education_discussion/molecule_of_the_month/index.html Molecule of the Month] feature on ''Tetrahydrobiopterin Biosynthesis'' by David Goodsell is [https://dx.doi.org/10.2210/rcsb_pdb/mom_2015_8 10.2210/rcsb_pdb/mom_2015_8]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1SEP OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1SEP FirstGlance]. <br>

</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=BIO:BIOPTERIN'>BIO</scene>, <scene name='pdbligand=NAP:NADP+NICOTINAMIDE-ADENINE-DINUCLEOTIDE+PHOSPHATE'>NAP</scene></td></tr>

<tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[https://en.wikipedia.org/wiki/Sepiapterin_reductase_(L-erythro-7,8-dihydrobiopterin_forming) Sepiapterin reductase (L-erythro-7,8-dihydrobiopterin forming)], with EC number [https://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.1.1.153 1.1.1.153] </span></td></tr>

[[https://www.uniprot.org/uniprot/SPRE_MOUSE SPRE_MOUSE]] Catalyzes the final one or two reductions in tetra-hydrobiopterin biosynthesis to form 5,6,7,8-tetrahydrobiopterin.

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== Publication Abstract from PubMed ==

Sepiapterin reductase catalyses the last steps in the biosynthesis of tetrahydrobiopterin, the essential co-factor of aromatic amino acid hydroxylases and nitric oxide synthases. We have determined the crystal structure of mouse sepiapterin reductase by multiple isomorphous replacement at a resolution of 1.25 A in its ternary complex with oxaloacetate and NADP. The homodimeric structure reveals a single-domain alpha/beta-fold with a central four-helix bundle connecting two seven-stranded parallel beta-sheets, each sandwiched between two arrays of three helices. Ternary complexes with the substrate sepiapterin or the product tetrahydrobiopterin were studied. Each subunit contains a specific aspartate anchor (Asp258) for pterin-substrates, which positions the substrate side chain C1'-carbonyl group near Tyr171 OH and NADP C4'N. The catalytic mechanism of SR appears to consist of a NADPH-dependent proton transfer from Tyr171 to the substrate C1' and C2' carbonyl functions accompanied by stereospecific side chain isomerization. Complex structures with the inhibitor N-acetyl serotonin show the indoleamine bound such that both reductase and isomerase activity for pterins is inhibited, but reaction with a variety of carbonyl compounds is possible. The complex structure with N-acetyl serotonin suggests the possibility for a highly specific feedback regulatory mechanism between the formation of indoleamines and pteridines in vivo.

The 1.25 A crystal structure of sepiapterin reductase reveals its binding mode to pterins and brain neurotransmitters.,Auerbach G, Herrmann A, Gutlich M, Fischer M, Jacob U, Bacher A, Huber R EMBO J. 1997 Dec 15;16(24):7219-30. PMID:9405351<ref>PMID:9405351</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 1sep" style="background-color:#fffaf0;"></div>

== References ==

<references/>

[[Category: Lk3 transgenic mice]]

[[Category: Auerbach, G]]

[[Category: Bacher, A]]

[[Category: Fischer, M]]

[[Category: Guetlich, M]]

[[Category: Herrmann, A]]

[[Category: Huber, R]]

[[Category: Jacob, U]]

[[Category: Tetrahydrobiopterin]]