Molecular cloning, sequencing, and expression of a cDNA encoding α-glucosidase from Mucor javanicus

A cDNA encoding Mucor javanicus α-glucosidase was cloned and sequenced by the reverse transcription-polymerase chain reaction and rapid amplification of cDNA ends methods. The cDNA comprised 2,751 bp, and included an open reading frame which encodes a polypeptide of 864 amino acid residues with a molecular mass of 98,759 Da. The deduced amino acid sequence showed homology to fungal and mammalian α-glucosidases and related enzymes, and the sequence around the putative active site was well conserved among these enzymes. The cloned gene was expressed in Escherichia coli cells to produce the α-glucosidase, which hydrolyzes not only maltose, but also soluble starch.