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-Structure paper
Title | Structure of the priming arabinosyltransferase AftA required for AG biosynthesis of . |
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Journal, issue, pages | Proc Natl Acad Sci U S A, Vol. 120, Issue 23, Page e2302858120, Year 2023 |
Publish date | Jun 6, 2023 |
Authors | Yicheng Gong / Chuancun Wei / Jun Wang / Nengjiang Mu / Qinhong Lu / Chengyao Wu / Ning Yan / Huifang Yang / Yao Zhao / Xiuna Yang / Sudagar S Gurcha / Natacha Veerapen / Sarah M Batt / Zhiqiang Hao / Lintai Da / Gurdyal S Besra / Zihe Rao / Lu Zhang / |
PubMed Abstract | Arabinogalactan (AG) is an essential cell wall component in mycobacterial species, including the deadly human pathogen . It plays a pivotal role in forming the rigid mycolyl-AG-peptidoglycan core for ...Arabinogalactan (AG) is an essential cell wall component in mycobacterial species, including the deadly human pathogen . 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 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 AG biosynthesis. Our data further provide a unique perspective into anti-TB drug discovery. |
External links | Proc Natl Acad Sci U S A / PubMed:37252995 / PubMed Central |
Methods | EM (single particle) |
Resolution | 3.1 Å |
Structure data | EMDB-35410, PDB-8if8: |
Chemicals | ChemComp-CA: |
Source |
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Keywords | MEMBRANE PROTEIN / Arabinosyltransferase / AftA / Mycobacterium tuberculosis |