RRC ID 48010
Author Katafuchi Y, Li Q, Tanaka Y, Shinozuka S, Kawamitsu Y, Izumi M, Ekino K, Mizuki K, Takegawa K, Shibata N, Goto M, Nomura Y, Ohta K, Oka T.
Title GfsA is a β1,5-galactofuranosyltransferase involved in the biosynthesis of the galactofuran side chain of fungal-type galactomannan in Aspergillus fumigatus.
Journal Glycobiology
Abstract Previously, we reported that GfsA is a novel galactofuranosyltransferase involved in the biosynthesis of O-glycan, the proper maintenance of fungal morphology, the formation of conidia and anti-fungal resistance in Aspergillus nidulans and A. fumigatus (Komachi Y et al., 2013. GfsA encodes a novel galactofuranosyltransferase involved in biosynthesis of galactofuranose antigen of O-glycan in Aspergillus nidulans and Aspergillus fumigatus. Mol. Microbiol. 90:1054-1073). In the present paper, to gain an in depth-understanding of the enzymatic functions of GfsA in A. fumigatus (AfGfsA), we established an in vitro assay to measure galactofuranosyltransferase activity using purified AfGfsA, UDP-α-d-galactofuranose as a sugar donor, and p-nitrophenyl-β-d-galactofuranoside as an acceptor substrate. LC/MS, 1H-NMR and methylation analyses of the enzymatic products of AfGfsA revealed that this protein has the ability to transfer galactofuranose to the C-5 position of the β-galactofuranose residue via a β-linkage. AfGfsA requires a divalent cation of manganese for maximal activity and consumes UDP-α-d-galactofuranose as a sugar donor. Its optimal pH range is 6.5-7.5 and its optimal temperature range is 20-30°C. 1H-NMR, 13C-NMR and methylation analyses of fungal-type galactomannan extracted from the ∆AfgfsA strain revealed that AfGfsA is responsible for the biosynthesis of β1,5-galactofuranose in the galactofuran side chain of fungal-type galactomannan. Based on these results, we conclude that AfGfsA acts as a UDP-α-d-galactofuranose: β-d-galactofuranoside β1,5-galactofuranosyltransferase in the biosynthetic pathway of galactomannans.
Volume 27(6)
Pages 568-581
Published 2017-6-1
DOI 10.1093/glycob/cwx028
PII 3091656
PMID 28369326
MeSH Aspergillus fumigatus / enzymology* Fungal Polysaccharides / chemistry Fungal Polysaccharides / metabolism* Fungal Proteins / chemistry Fungal Proteins / genetics Fungal Proteins / metabolism* Furans / chemistry Furans / metabolism Galactose / analogs & derivatives Galactosyltransferases / chemistry Galactosyltransferases / genetics Galactosyltransferases / metabolism* Manganese / chemistry Mannans / chemistry Mannans / metabolism
IF 4.06
Times Cited 14
Prokaryotes E. coli JW2021-AM