View source for 4wh3


==N-acetylhexosamine 1-kinase in complex with ATP==
<StructureSection load='4wh3' size='340' side='right'caption='[[4wh3]], [[Resolution|resolution]] 1.80&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4wh3]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Bifidobacterium_longum_subsp._longum_JCM_1217 Bifidobacterium longum subsp. longum JCM 1217]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4WH3 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4WH3 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]] 1.8&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=ACY:ACETIC+ACID'>ACY</scene>, <scene name='pdbligand=ATP:ADENOSINE-5-TRIPHOSPHATE'>ATP</scene>, <scene name='pdbligand=GOL:GLYCEROL'>GOL</scene>, <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene>, <scene name='pdbligand=MSE:SELENOMETHIONINE'>MSE</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=4wh3 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4wh3 OCA], [https://pdbe.org/4wh3 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4wh3 RCSB], [https://www.ebi.ac.uk/pdbsum/4wh3 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4wh3 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/NAHK_BIFL2 NAHK_BIFL2] Phosphorylates both N-acetylglucosamine (GlcNAc) and N-acetylgalactosamine (GalNAc) at similar rates. Involved in the lacto-N-biose I/galacto-N-biose (LNB/GNB) degradation pathway, which is important for host intestinal colonization by bifidobacteria. Also accepts GTP and ITP as phosphate donors. In vitro, can phosphorylate several GlcNAc and GalNAc derivatives.<ref>PMID:17720833</ref> <ref>PMID:19436918</ref> <ref>PMID:19683921</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Infant gut-associated bifidobacteria possess a metabolic pathway to utilize lacto-N-biose (Gal-beta1,3-GlcNAc) and galacto-N-biose (Gal-beta1,3-GalNAc) from human milk and glycoconjugates specifically. In this pathway, N-acetylhexosamine 1-kinase (NahK) catalyzes the phosphorylation of GlcNAc or GalNAc at the anomeric C1 position with ATP. Crystal structures of NahK have only been determined in the closed state. In this study, we determined open state structures of NahK in three different forms (apo, ADP complex, and ATP complex). A comparison of the open and closed state structures revealed an induced fit structural change defined by two rigid domains. ATP binds to the small N-terminal domain, and binding of the N-acetylhexosamine substrate to the large C-terminal domain induces a closing conformational change with a rotation angle of 16 degrees . In the nucleotide binding site, two magnesium ions bridging the alpha-gamma and beta-gamma phosphates were identified. A mutational analysis indicated that a residue coordinating both of the two magnesium ions (Asp228) is essential for catalysis. The involvement of two magnesium ions in the catalytic machinery is structurally similar to the catalytic structures of protein kinases and aminoglycoside phosphotransferases, but distinct from the structures of other anomeric kinases or sugar 6-kinases. These findings help to elucidate the possible evolutionary adaptation of substrate specificities and induced fit mechanism.

Open-close structural change upon ligand binding and two magnesium ions required for the catalysis of N-acetylhexosamine 1-kinase.,Sato M, Arakawa T, Nam YW, Nishimoto M, Kitaoka M, Fushinobu S Biochim Biophys Acta. 2015 Jan 30;1854(5):333-340. doi:, 10.1016/j.bbapap.2015.01.011. PMID:25644306<ref>PMID:25644306</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 4wh3" style="background-color:#fffaf0;"></div>
== References ==
<references/>
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</StructureSection>
[[Category: Bifidobacterium longum subsp. longum JCM 1217]]
[[Category: Large Structures]]
[[Category: Arakawa T]]
[[Category: Fushinobu S]]
[[Category: Kitaoka M]]
[[Category: Nam YW]]
[[Category: Nishimoto M]]
[[Category: Sato M]]