Use of Synthetic Glycolipids to Probe the Number and Position of Arabinan Chains on Mycobacterial Arabinogalactan
Autor: | Avraham Liav, Michael R. McNeil, Todd L. Lowary, Shiva K. Angala, Maju Joe, Mary Jackson |
---|---|
Rok vydání: | 2020 |
Předmět: |
0301 basic medicine
Spectrometry Mass Electrospray Ionization Stereochemistry Galactans 01 natural sciences Biochemistry Article Mycobacterium Cell wall 03 medical and health sciences chemistry.chemical_compound Residue (chemistry) Tandem Mass Spectrometry Arabinogalactan Carbohydrate Conformation biology 010405 organic chemistry Mycobacterium smegmatis General Medicine Galactan biology.organism_classification 0104 chemical sciences 030104 developmental biology Carbohydrate Sequence chemistry Molecular Probes Molecular Medicine Peptidoglycan Glycolipids ARAF Bacterial outer membrane Chromatography Liquid |
Zdroj: | ACS Chem Biol |
ISSN: | 1554-8937 1554-8929 |
DOI: | 10.1021/acschembio.0c00765 |
Popis: | The arabinogalactan of Corynebacterianeae is a critical heteropolysaccharide that tethers outer membrane mycolic acids to peptidoglycan thus forming the characteristic cell wall core of these prokaryotes. An essential α-(1→5)-arabinosyltransferase, AftA, is responsible for the transfer of the first arabinofuranosyl (Araf) unit of the arabinan domain to the galactan backbone of arabinogalactan, but the number and precise position at which Araf residue(s) is/are added in mycobacteria remain ill-defined. Using membrane preparations from Mycobacterium smegmatis overexpressing aftA, farnesyl-phospho-arabinose as an Araf donor, and a series of synthetic galactan acceptors of various lengths, we here show that a single priming arabinosyl residue substitutes the C-5 position of a precisely positioned internal 6-linked galactofuranosyl residue of the galactan acceptors, irrespective of their length. This unexpected result suggests that, like the structurally related mycobacterial lipoarabinomannans, the arabinogalactan of mycobacteria may in fact harbor a single arabinan chain. |
Databáze: | OpenAIRE |
Externí odkaz: |