Cloning and sequencing of beta-mannosidase gene from Aspergillus aculeatus no. F-50.

The manB gene, coding for a unique beta-mannosidase (MANB) of Aspergillus aculeatus, was cloned from genomic and cDNA libraries, and sequenced. The gene consists of 2,811 bp encoding a polypeptide of 937 amino acid residues with a molecular mass of 104,214 Da. The A. aculeatus MANB shared amino acid sequence identity with MANB of human (24%), goat (24%), bovine (24%), and Caenorhabditis elegans (22%). When the A. aculeatus MANB was compared with other related enzymes, a Glu residue corresponding to the active site identified by the Escherichia coli beta-galactosidase and the human beta-guclonidase was conserved. This is the first fungal gene that encodes MANB.