Papers

Peer-reviewed
Sep, 2015

Identification and Characterization of a Novel Galactofuranose-Specific beta-D-Galactofuranosidase from Streptomyces Species

PLOS ONE
  • Emiko Matsunaga
  • ,
  • Yujiro Higuchi
  • ,
  • Kazuki Mori
  • ,
  • Nao Yairo
  • ,
  • Takuji Oka
  • ,
  • Saki Shinozuka
  • ,
  • Kosuke Tashiro
  • ,
  • Minoru Izumi
  • ,
  • Satoru Kuhara
  • ,
  • Kaoru Takegawa

Volume
10
Number
9
Language
English
Publishing type
Research paper (scientific journal)
DOI
10.1371/journal.pone.0137230
Publisher
PUBLIC LIBRARY SCIENCE

beta-D-galactofuranose (Galf) is a component of polysaccharides and glycoconjugates and its transferase has been well analyzed. However, no beta-D-galactofuranosidase (Galf-ase) gene has been identified in any organism. To search for a Galf-ase gene we screened soil samples and discovered a strain, identified as a Streptomyces species by the 16S ribosomal RNA gene analysis, that exhibits Galf-ase activity for 4-nitrophenyl beta-D-galactofuranoside (pNP-beta-D-Galf) in culture supernatants. By draft genome sequencing of the strain, named JHA19, we found four candidate genes encoding Galf-ases. Using recombinant proteins expressed in Escherichia coli, we found that three out of four candidates displayed the activity of not only Galf-ase but also alpha-L-arabinofuranosidase (Araf-ase), whereas the other one showed only the Galf-ase activity. This novel Galf-specific hydrolase is encoded by ORF1110 and has an optimum pH of 5.5 and a Km of 4.4 mM for the substrate pNP-beta-D-Galf. In addition, this enzyme was able to release galactose residue from galactomannan prepared from the filamentous fungus Aspergillus fumigatus, suggesting that natural polysaccharides could be also substrates. By the BLAST search using the amino acid sequence of ORF1110 Galf-ase, we found that there are homolog genes in both prokaryotes and eukaryotes, indicating that Galf-specific Galf-ases widely exist in microorganisms.

Link information
DOI
https://doi.org/10.1371/journal.pone.0137230
Web of Science
https://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=JSTA_CEL&SrcApp=J_Gate_JST&DestLinkType=FullRecord&KeyUT=WOS:000360688200036&DestApp=WOS_CPL
ID information
  • DOI : 10.1371/journal.pone.0137230
  • ISSN : 1932-6203
  • Web of Science ID : WOS:000360688200036

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