View source for 8if8


==Arabinosyltransferase AftA==
<StructureSection load='8if8' size='340' side='right'caption='[[8if8]], [[Resolution|resolution]] 3.10&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[8if8]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Mycobacterium_tuberculosis_H37Rv Mycobacterium tuberculosis H37Rv]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=8IF8 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=8IF8 FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Electron Microscopy, [[Resolution|Resolution]] 3.1&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CA:CALCIUM+ION'>CA</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=8if8 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=8if8 OCA], [https://pdbe.org/8if8 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=8if8 RCSB], [https://www.ebi.ac.uk/pdbsum/8if8 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=8if8 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/AFTA_MYCTU AFTA_MYCTU] Involved in the biosynthesis of the arabinogalactan (AG) region of the mycolylarabinogalactan-peptidoglycan (mAGP) complex, an essential component of the mycobacterial cell wall. Catalyzes the addition of the first key arabinofuranosyl (Araf) residue from the sugar donor decaprenyl-phospho-arabinose (DPA) on the C-5 of a 6-linked galactofuranosyl (Galf) of the galactan domain, thus 'priming' the galactan for further elaboration by other arabinofuranosyltransferases. It is not able to add an Araf residue to a terminal Galf.<ref>PMID:16595677</ref> <ref>PMID:18556798</ref> 
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== Publication Abstract from PubMed ==
Arabinogalactan (AG) is an essential cell wall component in mycobacterial species, including the deadly human pathogen Mycobacterium tuberculosis. It plays a pivotal role in forming the rigid mycolyl-AG-peptidoglycan core for in vitro growth. AftA is a membrane-bound arabinosyltransferase and a key enzyme involved in AG biosynthesis which bridges the assembly of the arabinan chain to the galactan chain. It is known that AftA catalyzes the transfer of the first arabinofuranosyl residue from the donor decaprenyl-monophosphoryl-arabinose to the mature galactan chain (i.e., priming); however, the priming mechanism remains elusive. Herein, we report the cryo-EM structure of Mtb AftA. The detergent-embedded AftA assembles as a dimer with an interface maintained by both the transmembrane domain (TMD) and the soluble C-terminal domain (CTD) in the periplasm. The structure shows a conserved glycosyltransferase-C fold and two cavities converging at the active site. A metal ion participates in the interaction of TMD and CTD of each AftA molecule. Structural analyses combined with functional mutagenesis suggests a priming mechanism catalyzed by AftA in Mtb AG biosynthesis. Our data further provide a unique perspective into anti-TB drug discovery.

Structure of the priming arabinosyltransferase AftA required for AG biosynthesis of Mycobacterium tuberculosis.,Gong Y, Wei C, Wang J, Mu N, Lu Q, Wu C, Yan N, Yang H, Zhao Y, Yang X, Gurcha SS, Veerapen N, Batt SM, Hao Z, Da L, Besra GS, Rao Z, Zhang L Proc Natl Acad Sci U S A. 2023 Jun 6;120(23):e2302858120. doi: , 10.1073/pnas.2302858120. Epub 2023 May 30. PMID:37252995<ref>PMID:37252995</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 8if8" style="background-color:#fffaf0;"></div>
== References ==
<references/>
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</StructureSection>
[[Category: Large Structures]]
[[Category: Mycobacterium tuberculosis H37Rv]]
[[Category: Gong YC]]
[[Category: Rao ZH]]
[[Category: Zhang L]]