View source for 6zmk


==Crystal structure of human GFAT-1 L405R==
<StructureSection load='6zmk' size='340' side='right'caption='[[6zmk]], [[Resolution|resolution]] 2.38&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[6zmk]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6ZMK OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6ZMK 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]] 2.382&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=G6Q:GLUCOSE-6-PHOSPHATE'>G6Q</scene>, <scene name='pdbligand=GLU:GLUTAMIC+ACID'>GLU</scene>, <scene name='pdbligand=SEP:PHOSPHOSERINE'>SEP</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=6zmk FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6zmk OCA], [https://pdbe.org/6zmk PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6zmk RCSB], [https://www.ebi.ac.uk/pdbsum/6zmk PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6zmk ProSAT]</span></td></tr>
</table>
== Disease ==
[https://www.uniprot.org/uniprot/GFPT1_HUMAN GFPT1_HUMAN] Defects in GFPT1 are the cause of myasthenia, congenital, with tubular aggregates, type 1 (CMSTA1) [MIM:[https://omim.org/entry/610542 610542]. A congenital myasthenic syndrome characterized by onset of proximal muscle weakness in the first decade. Individuals with this condition have a recognizable pattern of weakness of shoulder and pelvic girdle muscles, and sparing of ocular or facial muscles. EMG classically shows a decremental response to repeated nerve stimulation, a sign of neuromuscular junction dysfunction. Affected individuals show a favorable response to acetylcholinesterase (AChE) inhibitors.<ref>PMID:21310273</ref> 
== Function ==
[https://www.uniprot.org/uniprot/GFPT1_HUMAN GFPT1_HUMAN] Controls the flux of glucose into the hexosamine pathway. Most likely involved in regulating the availability of precursors for N- and O-linked glycosylation of proteins.
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The hexosamine pathway (HP) is a key anabolic pathway whose product uridine 5'-diphospho-N-acetyl-D-glucosamine (UDP-GlcNAc) is an essential precursor for glycosylation processes in mammals. It modulates the ER stress response and HP activation extends lifespan in Caenorhabditis elegans. The highly conserved glutamine fructose-6-phosphate amidotransferase 1 (GFAT-1) is the rate-limiting HP enzyme. GFAT-1 activity is modulated by UDP-GlcNAc feedback inhibition and via phosphorylation by protein kinase A (PKA). Molecular consequences of GFAT-1 phosphorylation, however, remain poorly understood. Here, we identify the GFAT-1 R203H substitution that elevates UDP-GlcNAc levels in C. elegans. In human GFAT-1, the R203H substitution interferes with UDP-GlcNAc inhibition and with PKA-mediated Ser205 phosphorylation. Our data indicate that phosphorylation affects the interactions of the two GFAT-1 domains to control catalytic activity. Notably, Ser205 phosphorylation has two discernible effects: it lowers baseline GFAT-1 activity and abolishes UDP-GlcNAc feedback inhibition. PKA controls the HP by uncoupling the metabolic feedback loop of GFAT-1.

Protein kinase A controls the hexosamine pathway by tuning the feedback inhibition of GFAT-1.,Ruegenberg S, Mayr FAMC, Atanassov I, Baumann U, Denzel MS Nat Commun. 2021 Apr 12;12(1):2176. doi: 10.1038/s41467-021-22320-y. PMID:33846315<ref>PMID:33846315</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 6zmk" style="background-color:#fffaf0;"></div>

==See Also==
*[[Aminotransferase 3D structures|Aminotransferase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Atanassov I]]
[[Category: Baumann U]]
[[Category: Denzel MS]]
[[Category: Mayr F]]
[[Category: Miethe S]]
[[Category: Ruegenberg S]]