Abstract
The gene arfB encoding α-L-arabinofuranosidase B of the cellulolytic thermophile Clostridium stercorarium was expressed in Escherichia coli from a 2.2-kb EcoRI DNA fragment. The recombinant gene product ArfB was purified by fast-performance liquid chromatography. It has a tetrameric structure with a monomeric relative molecular mass of 52 00. The optima for temperature and pH are 70°C and 5.0 respectively. The enzyme appears to have no metal cofactor requirement and is sensitive to sulfhydryl reagents. It hydrolyzes aryl and alkyl α-L-arabinofuranosides and cleaves arabinosyl side-chains from arabinoxylan (oat-spelt xylan) and from xylooligosaccharides produced by recombinant endoxylanase XynA from the same organism. The identity of the N-terminal amino acid sequences indicates that ArfB corresponds to the major α-arabinosidase activity present in the culture supernatant of C. stecorarium.
Original language | English |
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Pages (from-to) | 856-860 |
Number of pages | 5 |
Journal | Applied Microbiology and Biotechnology |
Volume | 43 |
Issue number | 5 |
DOIs | |
State | Published - Oct 1995 |