View source for 8og4


==Exostosin-like 3 UDP complex==
<StructureSection load='8og4' size='340' side='right'caption='[[8og4]], [[Resolution|resolution]] 2.10&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[8og4]] 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=8OG4 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=8OG4 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]] 2.1&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=BMA:BETA-D-MANNOSE'>BMA</scene>, <scene name='pdbligand=CSO:S-HYDROXYCYSTEINE'>CSO</scene>, <scene name='pdbligand=MAN:ALPHA-D-MANNOSE'>MAN</scene>, <scene name='pdbligand=MN:MANGANESE+(II)+ION'>MN</scene>, <scene name='pdbligand=NAG:N-ACETYL-D-GLUCOSAMINE'>NAG</scene>, <scene name='pdbligand=UDP:URIDINE-5-DIPHOSPHATE'>UDP</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=8og4 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=8og4 OCA], [https://pdbe.org/8og4 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=8og4 RCSB], [https://www.ebi.ac.uk/pdbsum/8og4 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=8og4 ProSAT]</span></td></tr>
</table>
== Disease ==
[https://www.uniprot.org/uniprot/EXTL3_HUMAN EXTL3_HUMAN] Skeletal dysplasia-T-cell immunodeficiency-developmental delay syndrome. The disease is caused by variants affecting the gene represented in this entry.
== Function ==
[https://www.uniprot.org/uniprot/EXTL3_HUMAN EXTL3_HUMAN] Glycosyltransferase which regulates the biosynthesis of heparan sulfate (HS) (PubMed:28132690, PubMed:28148688). Initiates HS synthesis by transferring the first N-acetyl-alpha-D-glucosamine (alpha-GlcNAc) residue (GlcNAcT-I activity) to the tetrasaccharide linker (GlcA-Gal-Gal-Xyl-)Ser core linker (PubMed:11390981, PubMed:35676258). May also transfer alpha-GlcNAc residues during HS elongation (GlcNAcT-II activity) (PubMed:11390981, PubMed:35676258). Lacks glucuronyl transferase II (GlcAT-II) activity (PubMed:11390981, PubMed:35676258). Important for both skeletal development and hematopoiesis, through the formation of HS proteoglycans (HSPGs) (PubMed:11390981, PubMed:22727489, PubMed:28132690, PubMed:28148688, PubMed:35676258). Through the synthesis of HS, regulates postnatal pancreatic islet maturation and insulin secretion (By similarity).[UniProtKB:Q9WVL6]<ref>PMID:11390981</ref> <ref>PMID:22727489</ref> <ref>PMID:28132690</ref> <ref>PMID:28148688</ref> <ref>PMID:35676258</ref>   Receptor for REG3A, REG3B and REG3G, induces the activation of downstream signaling pathways such as PI3K-AKT or RAS-RAF-MEK-ERK signaling pathway (PubMed:22727489, PubMed:27830702, PubMed:34099862). Required for the function of REG3A in regulating keratinocyte proliferation and differentiation (PubMed:22727489). Required for the inhibition of skin inflammation mediated by REG3A through the activation of PI3K-AKT-STAT3 pathway (PubMed:27830702). Required for the function of REG3A and REG3G in glucose tolerance in pancreas (PubMed:19158046). Expressed in microglia, is activated by nociceptor-derived REG3G in response to endotoxins, leading to the inhibition of kynurenine pathway to prevent endotoxic death (By similarity).[UniProtKB:Q9WVL6]<ref>PMID:19158046</ref> <ref>PMID:22727489</ref> <ref>PMID:27830702</ref> <ref>PMID:34099862</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Two major glycosaminoglycan types, heparan sulfate (HS) and chondroitin sulfate (CS), control many aspects of development and physiology in a type-specific manner. HS and CS are attached to core proteins via a common linker tetrasaccharide, but differ in their polymer backbones. How core proteins are specifically modified with HS or CS has been an enduring mystery. By reconstituting glycosaminoglycan biosynthesis in vitro, we establish that the CS-initiating N-acetylgalactosaminyltransferase CSGALNACT2 modifies all glycopeptide substrates equally, whereas the HS-initiating N-acetylglucosaminyltransferase EXTL3 is selective. Structure-function analysis reveals that acidic residues in the glycopeptide substrate and a basic exosite in EXTL3 are critical for specifying HS biosynthesis. Linker phosphorylation by the xylose kinase FAM20B accelerates linker synthesis and initiation of both HS and CS, but has no effect on the subsequent polymerisation of the backbone. Our results demonstrate that modification with CS occurs by default and must be overridden by EXTL3 to produce HS.

Molecular mechanism of decision-making in glycosaminoglycan biosynthesis.,Sammon D, Krueger A, Busse-Wicher M, Morgan RM, Haslam SM, Schumann B, Briggs DC, Hohenester E Nat Commun. 2023 Oct 13;14(1):6425. doi: 10.1038/s41467-023-42236-z. PMID:37828045<ref>PMID:37828045</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 8og4" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Hohenester E]]
[[Category: Sammon D]]