Cooperation between β‐galactosidase and an isoprimeverose‐producing oligoxyloglucan hydrolase is key for xyloglucan degradation inAspergillus oryzae

The galactosylation of xyloglucan blocks many of the enzymatic processes targeting this oligosaccharide. We found that the expression of a gene encoding Aspergillus oryzae β‐galactosidase (LacA) is induced in the presence of xyloglucan oligosaccharides. With detailed analyses of the substrate specificity of purified recombinant LacA, we show that LacA cleaves galactopyranosyl residues from xyloglucan oligosaccharides, but not from xyloglucan...